3d Printed Shotgun Wads

[mikehill85]

I have been casting and reloading the Lyman 525 slugs for a bit over a year now. To save money I have basically just been using Walmart Field and Target multi-purpose loads, pouring out the lead, casting the lead into the 525 slugs and re-crimping them (fold crimp). I am currently getting ~4" groups at 50 yards.

I think some of the major accuracy problems with this slug and using a shotcup as a sabot are 1. Shredded wad petals and 2. The diameter of the driving bands on the slug. I am an Engineer and have a 3d printer. I was considering increasing the diameter of the front portion of the Lyman 525 slug by 3d printing a cap for the front portion of the slug, out of nylon, which would bring the front driving band up to 0.72 inches (a bit less than bore diameter for safety), a rear truncated cone to fill the cavity with a ball on the end similar to the Truball slug and printing my own wad with a recess for the ball similar to the Truball slug. I would actually just copy the Truball slug wad in a program like Fusion360.

Any thoughts on whether this is a terrible idea or not? Is 0.72 inches too big or too small for the front driving band?

[gpidaho]

Mike: The printed cap to bring the Lyman sabot slug up to a bore sized slug sounds interesting. I shoot cylinder bore or rifled slug barrels so .720 sounds small to me. In my smooth bore cylinder barrels I shoot up to .737 round ball. The Lyman doesn't have a very large drive band so my thought is that the cap should bring the size up in the .730 range. Take all this knowing that I'm no expert at all this, just sharing my thoughts. Gp

[mikehill85]

Thanks for the input. The choke tube with the least constriction I have is improved cylinder bore so I thought it might be best to make it 0.72” because that’s the diameter of the choke tube but in reality I’m sure 0.73 is fine too, especially if I put “rifling” in cap the design to give it some wiggle room like in “rifled” slugs.

[littlejack]

Mike:
So, you are saying you are going to do away with the shot cup altogether,
then you are going to enlarge the front driving band diameter of the projectile via a cup over the front end, Yes? Then, you're going to make a cavity filler piece with a oversized base wad attached, right? So, the base of the original slug would still be undersize (as cast) but your 3d wad would be bore size, except for the cavity filler in front, right? Mike, that is a real mindbender. I understand the concept, but that sounds like a lot of work.
Now, back to the basics. Before you insert the substituted slug for the shot, have you removed the wad from the shell, and made sure the wad petals are the correct thickness for the slug. The Lyman slug, has two (2) diameters. The front driving band is approximatey .010 larger than the skirt diameter. Therefore, the cup petals need to be two different thicknesses, to accommodate the two diameters of the slug. This may be why you are getting shredded petals on the wad cups.
Anyway, "Necessity is the mother of invention". You are trying something completely different. Not a darn thing wrong with that. I'm posting another procedure I'm going to try with the Lyman slugs. You may be Interested.
Let me know if I understood your procedure correctly.
All the best in your endever sir.

[mikehill85]

Yes, I think you've understood me right. I would take out the old wad with shotcup and put in a new one which is basically a copy of the federal tru ball slug wad. I would have a cavity filler like the ball in the truball slugs and I would have a cap that brings the front of the slug up to bore diameter. The slug should be centered at the front by the cap and at the back by the wad. The ball should ensure separation from the wad.

It might not even be necessary to have a custom wad, it is possible I could just cut the petals off a wad with shotcup, fill in the cavity to make sure that wad doesn't get stuck in the back of the slug (creating flyers), extend this down a bit and around the rear of the Lyman slug bringing the back driving band up to bore diameter as well. I may try this first as a test as it is much simpler.

Ideally, it would be very cool the be able to make relatively accurate slugs (at least within 50 yards) by just using re-purposing super cheap birdshot shells and modifying the Lyman 525 a bit with plastic parts that cost next to nothing. I don't know if it is possible due to the relatively low muzzle velocity the slug starts at. It may be the worst enemy of accuracy is that the slug may become unstable in the trans-sonic region but I am willing to try out my idea.

Anyway, I already modeled the Lyman 525 Slug in Fusion360. Modeling the cap is child's play at this point. I will post some screen grabs of the model and photos of the cap once I get it printed for those interested.

Sure thing, I would definitely be interested in anything you have cooking with the Lyman slug.

[littlejack]

Most of the Lyman slug shooters, fill the cavity with hot glue. Then trim off the excess flat. This works very well keeping the wad from pushing up into the slug cavity. I have about 50 I filled today, and have to trim off.
Very interesting process you have going there.

[pashiner]

The russians make a fullbore version of that slug too. Probably a little heavy for re-stuffing a walmart shell though. Have you considered making the cavity filler a slightly more acute taper than the inside of the slug? This might serve to obturate the skirt, and provide more bearing surface, and a bit more cushion for the pushing. I'd worry about the base wad taking the place of the factory cushion section and possibly upping pressures.

[littlejack]

Years ago, I was experimenting with the Lyman .69 conical in my 12 gauge loads.
It crossed my mind that the base of the boolit needed something to push it Into the rifling upon ignition. Thats the way the hollow cavity was designed, when the black powder exploded under it. Setting the conical in a shot cup was a complete failure. The loads with the .69, shot 1 moa. Thats "minute of brontosaurus"

[littlejack]

Pashiner:
Your comment on the acute taper cavity filler seems like a very valid option.

[mikehill85]

The russians make a fullbore version of that slug too. Probably a little heavy for re-stuffing a walmart shell though. Have you considered making the cavity filler a slightly more acute taper than the inside of the slug? This might serve to obturate the skirt, and provide more bearing surface, and a bit more cushion for the pushing. I'd worry about the base wad taking the place of the factory cushion section and possibly upping pressures.

This is what it currently looks like. You are saying that perhaps I should make the angle on the base a bit more flared outwards to force the skirt open and not extending to bore diameter on the base (pink area)?

241822

241823

[Hogtamer]

i found that soft lead using glue filled base get enought kick in the butt at 1400+ fps to fill bore nicely.

[mikehill85]

FYI, a photo of the parts on the slug, 3D printed in PLA. I plan on printing them in nylon. These are rough since I printed only in and the plastic was too hot but gives you an idea what it looks like.

241833
241834

[mikehill85]

i found that soft lead using glue filled base get enought kick in the butt at 1400+ fps to fill bore nicely.

Thanks for the tip. I would guess whether or not it has enough kick would also be dependent on your powder burn rate as well, no?

[W.R.Buchanan]

This is interesting. How about a two piece Sabot that fits the slug and is about .730 when both halves are together around the slug.

Kind of like this. see pics This is a disassembled Lightfield Slug and these are supposed to be the most accurate slugs out there.

Doing the same thing with the Lyman Slug might work.

Randy

[Markopolo]

Looks like a cap, and a gown... And what would the cap be good for other then bore diam? Are you sure you would need it on the top of the slug like that??? Personally would try it without the cap as well as with the cap. Just wondering is all...

[Hogtamer]

The birdshot shells you're using does have a relatively fast burning powder. 37 gr longshot in a fed gold medal hull (lyman book load calls for up to 39) is a different animal, but with bases filled the base of the wad remains in good shape.

[mikehill85]

You are correct. The only point is to make it bore diameter. I was just trying to ensure that the slug is held in the same orientation whenever it leaves the barrel. Constraining the front and rear of the slug should help ensure that.

Very cool slug design you have there. I was wondering if it is for rifled barrels or is it just air pressure that forces it open when it leaves the barrel.

[littlejack]

The sabot would fall away by design, whether sent from a rifled or smooth bore.
I was wandering, although your 3D design looks good, would there be any chance of the base wedge and cup being dragged off by friction going down the bore?

[longbow]

I am thinking it is easier all around just to cast a bore diameter slug... actually a bit over bore diameter for crush fit would be best. If you have the Lyman mould and a 3D printer and want to play there is nothing wrong with that but I'd suggest making the caps for both ends a snap fit if they are likely to come off in flight. The plastic will get squished some as the slug obturates and if the capped slug is under bore diameter it will rattle down the bore and pound the plastic. If over bore diameter with the plastic of course the plastic will squish some. A snap fit should keep it in place either way.

If you take a look at recovered wads after firing birdshot or slugs they tend to extrude or shear where squeezed. You need a tough plastic and something to keep it in place (back to the snap fit)... I think anyway.

Now that we are onto making slug parts to center the slug in the bore, what sort of tolerances and consistency are you able to get with the 3D printed parts? If it is +/- a couple thou then I'd definitely recommend slugging the bore and making sure the finished parts are a couple thou over bore diameter at the minus end so you are guaranteed a squeeze fit.

And speaking of sabots, could you 3D print a split sabot like the Lightfield slug so the entire slug sits inside a 2 or 3 piece sabot? that might be better than the caps. I think it would be.

My thoughts anyway.

Keep us posted on results please.

Longbow

[mikehill85]

Well I thought the back would stay in place by the pressure at the back and the front would be forced in place by friction. I also planned on using steel wool to rough up the surfaces they are in contact with and super gluing them in place. With the extreme G forces it may not make any difference whatsoever but I thought I’d try it.

[littlejack]

I would say, the only real way to find out would be to start making and loading.
But, as Longbow stated, it would be a lot easier to just cast a bore diameter slug.

[mikehill85]

I would say, the only real way to find out would be to start making and loading.
But, as Longbow stated, it would be a lot easier to just cast a bore diameter slug.

Agreed. I will print the current configuration in nylon tomorrow and go to the range on Saturday. I have good data from last week for comparison. If this doesn’t help I will try the Lightfield configuration.

[littlejack]

Looking forward to the results of your labors.

[Cap'n Morgan]

Good luck with your experiments. Tinkering with slugs is FUN!

I have toyed with the idea of using a snap-on wad and ballistic cap (like seen on bottle rockets) on lathe turned steel or brass slugs. Using steel/brass instead of lead would solve the two main problems with lead slugs; Too much weight in full bore slugs and and the tendency of the skirt of hollow base slugs to deform under pressure. While turned slugs probably would be of little interest to the common slug reloader, a cast zinc slug combined with 3-D printed "bore guides" would certainly be possible.

[mikehill85]

Good luck with your experiments. Tinkering with slugs is FUN!

I have toyed with the idea of using a snap-on wad and ballistic cap (like seen on bottle rockets) on lathe turned steel or brass slugs. Using steel/brass instead of lead would solve the two main problems with lead slugs; Too much weight in full bore slugs and and the tendency of the skirt of hollow base slugs to deform under pressure. While turned slugs probably would be of little interest to the common slug reloader, a cast zinc slug combined with 3-D printed "bore guides" would certainly be possible.

Agreed, slugs are a lot of fun. They are probably the most practical projectile for tinkering because of their large size. That ballistic cap you are talking about, was that for drag reduction? I was thinking about this as well. The Lyman 525 in particular must have an abysmal ballistic coefficient due to the flat nose. One would think that adding a more rounded profile would help.
The thing is, you don't want to mess with the center of pressure on these drag stabilized slugs too much (which I may have already done...hopefully not) or they will become unstable. The center of pressure should be behind the center of mass for self-correcting projectiles. Actually you can see the location of the center of mass in the screenshot I posted on page 1. I have CFD software that can calculate the center of pressure, drag, ect. as well. I may get into that as I continue to play around with these designs. Below is a tutorial from that software for those interested. It shows some pretty cool results for the pressure and velocities around the bullet they are modeling.
https://knowledge.autodesk.com/support/cfd/learn-explore/caas/CloudHelp/cloudhelp/2014/ENU/SimCFD/files/GUID-6195CF4E-FB5F-421A-A12E-EBDCB397B479-htm.html

[mikehill85]

I am thinking it is easier all around just to cast a bore diameter slug... actually a bit over bore diameter for crush fit would be best. If you have the Lyman mould and a 3D printer and want to play there is nothing wrong with that but I'd suggest making the caps for both ends a snap fit if they are likely to come off in flight. The plastic will get squished some as the slug obturates and if the capped slug is under bore diameter it will rattle down the bore and pound the plastic. If over bore diameter with the plastic of course the plastic will squish some. A snap fit should keep it in place either way.

If you take a look at recovered wads after firing birdshot or slugs they tend to extrude or shear where squeezed. You need a tough plastic and something to keep it in place (back to the snap fit)... I think anyway.

Now that we are onto making slug parts to center the slug in the bore, what sort of tolerances and consistency are you able to get with the 3D printed parts? If it is +/- a couple thou then I'd definitely recommend slugging the bore and making sure the finished parts are a couple thou over bore diameter at the minus end so you are guaranteed a squeeze fit.

And speaking of sabots, could you 3D print a split sabot like the Lightfield slug so the entire slug sits inside a 2 or 3 piece sabot? that might be better than the caps. I think it would be.

My thoughts anyway.

Keep us posted on results please.

Longbow

I think your idea of snap fit is a a very good one and something I should be able to do fairly easily with a very slight modification to the design. The tolerance on the printer is +- 0.0039 in the xy plane.

I chose nylon for the material because it is an extremely tough high temperature plastic which has great inter-layer adhesion (i.e. bonding between the printed layers) and it is used in so-called self-lubricating parts. The main reason I chose it though is because it is used as the driving band material in Armour-piercing discarding sabot tank rounds such as those used by the M1. I figure if it can survive being fired out of a 120 mm cannon at absurdly high velocities it can withstand a shotgun. The other good property it has is that, while it is firm/strong, it also has some flexibility.

As for the Lightfield sabot, do you have any experience with it? I was trying to determine the mechanism by which it separates, it looks like there are two tabs on either side of the slug which I assume are there to hold it in place on the way down the barrel, once it leaves the barrel I assume the air pressure just splits it open. Of course the pressure was there during the ride down the barrel but it couldn't open because the barrel was in the way. Is that your understanding?

[longbow]

A slug design I have liked and thought about is the Balle Sauvestre:

http://www.sauvestre.com/12-70,1381?lang=fr

Pretty much out of the home tinkerer's domain... until the advent of 3D printing.

Originally I liked the idea of the BRI sabot slug but they reportedly didn't stabilize from smoothbores well. Taofledermaus "proved them wrong" at least in their videos. My thought was to add a tailwad but Balle Sauvestre beat me to that! They have a pretty slick idea that apparently works well.

I have not tried either slug partly because they are hard to get where I am and partly because I am too cheap to pay for factory slugs and because I want to be able to do it myself. Also, I prefer bore size or near bore size slugs rather than a .50 or .60 cal. sabot slug. 12 ga. shotguns are big bore so let's shoot big bore slugs!

Now with 3D printing available some of these things are doable at home for those with 3D printers... you being one of those guys!

Not sure if you have seen BigMrTong's threads:

http://castboolits.gunloads.com/showthread.php?355115-Sabot-Rounds-in-12g-Shotgun
http://castboolits.gunloads.com/showthread.php?358525-Lee-7-8oz-Custom-Slug-Wads
http://castboolits.gunloads.com/showthread.php?364546-Improvement-of-my-Good-1oz-Lee-Slug-Load
http://castboolits.gunloads.com/showthread.php?371069-Surprising-10-gauge-Slug-Accuracy

He has played with Lee slugs and some home designed slugs using tail wads and sabots all 3D printed.

With the ability to 3D print I'd lean towards a full bore slug with tail wad or a Lightfield type sabot slug near full bore with tailwad. That's just me of course.

I'llbe watching to see what you come up with and field results. It is indeed fun playing with slugs!

Longbow

[mikehill85]

A slug design I have liked and thought about is the Balle Sauvestre:

http://www.sauvestre.com/12-70,1381?lang=fr

Pretty much out of the home tinkerer's domain... until the advent of 3D printing.

Originally I liked the idea of the BRI sabot slug but they reportedly didn't stabilize from smoothbores well. Taofledermaus "proved them wrong" at least in their videos. My thought was to add a tailwad but Balle Sauvestre beat me to that! They have a pretty slick idea that apparently works well.

I have not tried either slug partly because they are hard to get where I am and partly because I am too cheap to pay for factory slugs and because I want to be able to do it myself. Also, I prefer bore size or near bore size slugs rather than a .50 or .60 cal. sabot slug. 12 ga. shotguns are big bore so let's shoot big bore slugs!

Now with 3D printing available some of these things are doable at home for those with 3D printers... you being one of those guys!

Not sure if you have seen BigMrTong's threads:

http://castboolits.gunloads.com/showthread.php?355115-Sabot-Rounds-in-12g-Shotgun
http://castboolits.gunloads.com/showthread.php?358525-Lee-7-8oz-Custom-Slug-Wads
http://castboolits.gunloads.com/showthread.php?364546-Improvement-of-my-Good-1oz-Lee-Slug-Load
http://castboolits.gunloads.com/showthread.php?371069-Surprising-10-gauge-Slug-Accuracy

He has played with Lee slugs and some home designed slugs using tail wads and sabots all 3D printed.

With the ability to 3D print I'd lean towards a full bore slug with tail wad or a Lightfield type sabot slug near full bore with tailwad. That's just me of course.

I'llbe watching to see what you come up with and field results. It is indeed fun playing with slugs!

Longbow

The Sauvestre slug looks sick. The sabot release mechanism also doesn't require lead tabs like the Lightfield. I'll see how things go this weekend. Perhaps trying to copy the Sauvestre should be next thing I look at.

Thanks for the advice and links. I will keep you posted with results.

[Cap'n Morgan]

Mike, at one point I tinkered with a slug with a large meplat and it shoot alright out to 60 yards after which the groups would cease to be groups:

http://castboolits.gunloads.com/showthread.php?246413-Brenneke-slugs-light-at-the-end-of-the-tunnel&p=3408361&viewfull=1#post3408361

[longbow]

Cap'n Morgan:

Back to the "form" comments I made in another thread.

You seem to have a pretty good handle on slug design so I'll ask here:

What's your take on nose shape affecting flight/aerodynamics?

turbo1889 said the Lyman sabot slug with its big meplat becomes unstable at transonic velocity. I have no personal experience with it but because wadcutter boolits have that reputation I can believe it. Same would apply to many other slug designs with very large meplats like the ACE 740 gr.

I have to think that the large meplat exaggerates the blanket effect that Randy brought up and that a more streamlined nose shape of hemispherical, pointy like the Moose .69 Minie or SWC like would be more streamlined providing somewhat better BC and less blanket effect plus if the slug tips in flight the nose would have less drag than the skirt so better self correction.

I always wondered why Lyman didn't use a nose shape more like the Rapine slugs with TC nose. Personally I think it would have been better ~ talking for smoothbore here all the way.

Maybe our OP could 3D print a TC snap on nose for testing (hint, hint). It wouldn't add much weight (probably a good thing) and wouldn't help with moving CG forward but would make a more streamlined projectile.

Kinda thinking a profile like:

https://www.pyramydair.com/s/p/Crosman_Field_Hunting_22_Cal_14_3_Grains_Pointed_1 75ct/111

pointy but with a smallish meplat (nose pour anyway).

Longbow

[longbow]

By the way, I note your Brenneke slug in that thread that shot well for you has a quite large extended nose on it seemingly bigger than original Brenneke's. It worked very well. So now I have to ask why you didn't stick to that design?

And back on track something else the OP might experiment with is adding both "nose cone" and extended tail wad to his Lyman sabot slugs. Kind of a combination of BigMrTong's tail wad, extended nose cone and full bore slug all at once... but here I go trying to influence someone else's design. Just my thoughts and comments you can use or discard as you see fit.

I'll shut up now.

Longbow

[mikehill85]

Mike, at one point I tinkered with a slug with a large meplat and it shoot alright out to 60 yards after which the groups would cease to be groups:

http://castboolits.gunloads.com/showthread.php?246413-Brenneke-slugs-light-at-the-end-of-the-tunnel&p=3408361&viewfull=1#post3408361

Impressive results and good shooting. It definitely seems that once these types of slugs get to further distances and therefore lower velocities they start tumbling. It makes sense because they are drag stabilized and the loss of velocity means they can no longer self correct. Having a long tail like some Plumbata style slugs helps with this by moving the center of pressure further away from the center of gravity of the projectile. You're still losing drag at lower velocities but your center of pressure is further away to start with. At that point the issue becomes ensuring the tail stays attached and always exits the barrel in a similar shape.

Have you heard good things about the accuracy of the Sauvestre style slugs?

[mikehill85]

By the way, I note your Brenneke slug in that thread that shot well for you has a quite large extended nose on it seemingly bigger than original Brenneke's. It worked very well. So now I have to ask why you didn't stick to that design?

And back on track something else the OP might experiment with is adding both "nose cone" and extended tail wad to his Lyman sabot slugs. Kind of a combination of BigMrTong's tail wad, extended nose cone and full bore slug all at once... but here I go trying to influence someone else's design. Just my thoughts and comments you can use or discard as you see fit.

I'll shut up now.

Longbow

Long bow, I think those are very good ideas and actually things I had thought of as well. I asked for input and I'm glad we're thinking on the same lines. If the flat caps stay on I will definitely look at doing something like this.
The very flat nose of the Lyman 525 seems like it is begging to have a terrible ballistics coefficient. In the Lyman 525 slugs the large amount of weight at the front pulls the center of gravity forward and the flat bottom creates a vacuum that stabilizes the round. Adding a tail, even a flat disk tail should help to stabilize it at lower velocities.

I would guess that they may have designed it with a flat nose because they wanted the driving bands to be relatively close to bore diameter and didn't want to make the round preposterously heavy. It is already a pretty heavy slug as it is. When you think about it, the only way they could keep the overall mass the same and add more in the front would be to reduce the thickness of the skirt which they probably kept pretty thick on purpose to allow for safe obturation across a variety of loads and if the mass were too much higher than it is now it probably couldn't be used in shotcups as intended without crushing them into nothing.

Lol. If the slug gets anymore plastic modifications to its outward appearance it is going to become a Kardashian.

[Cap'n Morgan]

Cap'n Morgan:

Back to the "form" comments I made in another thread.

You seem to have a pretty good handle on slug design so I'll ask here:

What's your take on nose shape affecting flight/aerodynamics?


Longbow. Until I saw this picture below, I believed the more "pointy" the better. However, that is NOT the case when we're talking subsonic speed/drag. The most drag is produced by an open cylinder (1.0) and the least by an ordinary hemisphere (0.01) Interesting, a pointed 60 included angle has more drag (0.2) than the traditional ogive shape we find in boolits (0.05). I'll gladly admit that these numbers go against my first intuition and I do not know how these different shape values would affect the actual ballistic coefficient figure of the slug , but there you are...

https://i.imgur.com/IGmlABm.jpg

[W.R.Buchanan]

I think the whole point of the Lyman Slug is to give the home loader a slug that will be relatively accurate out to 50 or so yards and have serious knock down power. You know the flat nose is going to dump all it's energy very quickly, which for short range hunting would probably be the best thing you could ask for.

The Idea of the snap on nose piece and tail piece to bring it up to full bore size I think has merit in a Rifled barrel. I don't see any advantage from a smoothbore simply because you can duplicate the square launch with correct wads and nitro cards etc. Once the slug leaves the barrel the caps are going to disengage quickly from either a smooth or rifled barrel.

Won't know for sure until you try.

Randy

[Markopolo]

I am watching for results as well...

Of course I watch all these investigative shotgun slug threads. Better then reality shows any day...

[longbow]

Now then Marko you are laughing with us not at us right...? I hope so anyway!:p

Cap'n Morgan:

I can't argue the fluid dynamics but with shotgun slugs or boolits the conditions are varying along the flight path and BC changes with velocity as well as shape. A "projectile" in a steady flowing fluid stream of liquid or gas is in steady state condition where our slugs/boolits start out relatively fast then slow along the trajectory and shotgun slugs normally start out supersonic but somewhere around 50 yards or a little past, depending on starting velocity, they go transonic.

Also, the blunt shapes are better for subsonic velocities than pointy shapes. Some people load pointy boattail "J" bullets backwards for subsonic use for that reason. At supersonic velocity pointy boattail bullets are best shot point forwards.

Wadcutter boolits do not maintain stability over long range so I have to think that Lyman sabot slugs with their huge meplat are probably suffering from the same issue. I do remember turbo1889 saying that they become unstable at transonic velocity. Maybe if launched subsonic it isn't an issue. I do not have a Lyman mould so no personal experience there.

A hemispherical nose or RNFP with moderate meplat makes sense to me.

Also, I am not as concerned about BC as I am about drag on the body and skirt where in reality the more drag we get likely the better off we are so contrary to goo BC but good for self correcting drag. As Randy says, our shotgun slugs are short range projectiles so high BC is not really much of a plus. If I can get good accuracy to 100 or maybe 125 yards I'd be a happy guy and BC at that range isn't going to have a huge effect on trajectory. Let's face it, the Lyman slugs are proven out to 100 yards or better so if they can maintain lethal energy and acceptable trajectory then anything better is a bonus.

My understanding is that at supersonic velocity the shockwave moves back to the tail end but as the slug goes transonic the shockwave starts moving back up the body to the nose and there is a lot of turbulence going on at that point. I should do some reading I guess as I have very limited knowledge in that area.

Longbow

[Markopolo]

Are you kidding?? I love this stuff.. Never laffing at!... always learning and listing to what the real experts around here have to say. Sadly, I am Not one of the experts, but seek to glean whatever I can with my pea sized brain... I have fueled many experiments based on what I have seen and learned here... that is what I mean when I say, way better then reality shows.. what the heck can any learn from watching those???

[longbow]

That makes me feel better! I am a sensitive lad don't you know! Yes, lots to learn here... and the learning just keeps on going it seems. Lots of new young guys with shiny brains stepping in and showing new stuff too. It is all good fun and a great bunch of people here sharing and learning. Good stuff!

Longbow

[W.R.Buchanan]

LB: Have you started your "Tactical Training" yet? I want to hear frequent updates on how the gun handling is going.

I have to tell you that after learning how to run a Pump Gun fairly well, that the A5 transition came quickly. I was up to speed with that gun before the morning was over with on the first day of the class. Most all of what is covered in the book directly translates to the A5 other than not needing to port load it because of the Speed Feed Feature. But you can port load it as well.

You can learn most of this at home by Dry Practicing. Which you'll notice it says right on the cover. "Dry Practice Manual!"

Have fun this weekend er I guess you guys don't do Memorial Day up there, huh?

Randy

[longbow]

Randy... sorta! I started reading the book but as mentioned, I have been distracted by archery for a while now. We had our big shoot last weekend (3 day weekend here so 3 day shoot). All my recent effort has gone into that lately. It paid off though! I took 1st place in mens selfbow which is not a huge accomplishment since the field was only 7 but better, my score was competitive with the laminated recurve and long bow/carbon arrow shooters. I shoot a home made yew flatbow with home made self nocked wood arrows so when I can score up with the guys using laminated bows and carbon arrows I feel pretty good.

Most importantly though it was a terrific weekend meeting up with old archery friends again. This is a shoot I do not like to miss and don't very often... like twice in 20 years.

Now that's done I actually have one more shoot (maybe a couple yet). The North American Longbow Safari is coming up in July as well and I am not going to miss that one. It'll put a dent in my shotgun training and slug shooting but I'm going!

I'll get some slug shooting done for sure and I will read the book for sure along with doing some dry practice. I will read through the book to absorb what I can then do the dry practice after. I likely won't be spending enough time in the next month to be a super proficient "threat" with my slug gun though... but I'll get there!

Nope, no Memorial day but we did celebrate Queen Victoria's birthday last weekend. I celebrated at the archery range!

Longbow

[Markopolo]

Awwww LB.. congrats are in order, but without pics... It didn’t... [smilie=f:

[Hogtamer]

Kent, figure out how to put a radius fletching on these lead slugs when they exit the bore and all will be good!

[longbow]

The only pic I have:

242383

That's me in the back 3rd from right. All wood bow shooters except the dog.

It was a great weekend and a great bunch of shooters. This was one of the best turnouts we've had. This is an all traditional shoot so recurves, longbows and wood bows only. Everyone in the group photo except Gina (the little lady in the middle) made their own bow. Her husband made both their bows. The dog... well what can I say!?! He was fun though.

Longbow

[Markopolo]

Now THAATTTT is an awesome picture sir... very awesome!!!

[mikehill85]

Sorry for the delay. It took me longer than I thought to get my 3d printer settings dialed in to get me tolerances that I was comfortable shooting (Nylon can be a tricky material to print) I have some preliminary results. Please don't make fun of my groups too much. The 1st two are common store bought slugs to give you a feel for my general level of shooting (not great but I'm learning). I was only able to print enough parts for 5 wadcutter style slugs and 3 round nose slugs for this outing but now that I have things sorted out I should be able to print enough to get more solid data in the next week or so. These are the results for now. Make of them what you will. All shots are at 50 yards and it was pretty windy out today (17 mph wind)...my excuse for any flyers or any other type of poor shooting.


1st A 3 shot group with Remington "Slugger" Slugs
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2nd a 3 shot group with Truball Slugs.
242398
3rd a 5 shot group with the Lyman 525 slug replacing birdshot with the slug in cheap Walmart birdshot shells, as previously described in this post. The sabot in this case is the shotcup.
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4th a 5 shot group with the Lyman 525 slug using cheap Walmart birdshot shells, removing the shotcup and using the 3d printed wadcutter cap on the top and 3d printed skirt on the bottom. It looks like the shot in the upper left may be a flyer. I will need more data to say for sure.
242400
5th a 3 shot group with the Lyman 525 slug using cheap Walmart birdshot shells, removing the shotcup and using the 3d printed rounded cap (like a round nose pellet) on the top and 3d printed skirt on the bottom, please note the 3rd shot on the bottom here.
242401

I printed in red nylon and didn't see any caps or skirts out on the range try as I might to locate them. As far as I can tell they made it along with the slugs to the target and are buried in the berm along with the slugs. Also, it appears to me that the diameter of the holes from the slugs with 3d printed caps and skirts are larger.

[longbow]

Looks pretty good to me! The Remington Sluggers and Tru-Balls did quite well which is not a surprise. I've said many times if I could get the same accuracy as factory Fosters with my home cast slugs I'd be happy!

Your full bore wadcutters looked to do quite well excepting the flier. Even with it the group isn't bad but if it was with the other 4 that would be pretty impressive.

Remind me... you are shooting smoothbore right?

To be honest I would have thought the round nose cap would do better but so far a 3 shot group doesn't prove a lot. If everything else was the same except for caps it may be indicative though. If you get the same sort of grouping with that next time then I'd say it's one to leave behind.

I'd say you are off to a good start and certainly worth pursuing with more 50 yard groups then moving out to maybe 75 yards to see how groups hold up. That transonic instability thing may rear its head at some point.

Did you check fit of the Walmart shotcups and Lyman slugs? I'm guessing from the relatively poor accuracy of that group they weren't a really good fit.

Also, how are you opening crimps? Re-crimping ~ roll crimp? Fold crimp?

Interesting results! I'll be watching for more here!

By the way, my apologies for the archery thread drift.

Longbow

[mikehill85]

Looks pretty good to me! The Remington Sluggers and Tru-Balls did quite well which is not a surprise. I've said many times if I could get the same accuracy as factory Fosters with my home cast slugs I'd be happy!

Your full bore wadcutters looked to do quite well excepting the flier. Even with it the group isn't bad but if it was with the other 4 that would be pretty impressive.

Remind me... you are shooting smoothbore right?

To be honest I would have thought the round nose cap would do better but so far a 3 shot group doesn't prove a lot. If everything else was the same except for caps it may be indicative though. If you get the same sort of grouping with that next time then I'd say it's one to leave behind.

I'd say you are off to a good start and certainly worth pursuing with more 50 yard groups then moving out to maybe 75 yards to see how groups hold up. That transonic instability thing may rear its head at some point.

Did you check fit of the Walmart shotcups and Lyman slugs? I'm guessing from the relatively poor accuracy of that group they weren't a really good fit.

Also, how are you opening crimps? Re-crimping ~ roll crimp? Fold crimp?

Interesting results! I'll be watching for more here!

By the way, my apologies for the archery thread drift.

Longbow

Yeah, it's really unfortunate that I wasn't able to print more of the rounded caps. Also, the performance may not be indicative of their ideal performance. For one thing I printed these off in a rush and didn't print supports which means there was an unsupported area where the printer printed in the air, leaving a bunch of stringy filaments where the nose of the slug meets the back of the cap (the cap may have shifted positions after it left the barrel leading to inaccuracy). Also, I super glued all the parts on to the slugs but for the round nose slugs I just did it this morning so it's quite possible they weren't performing as well as they could because the glue didn't have time to fully cure, in any case, we'll see. I have high hopes for the round nose slugs. They should result in less drag at the nose of the slug which you'd think would aid in stability since they are drag stabilized at the tail. In the worst case, you'd think they would stay above the sound barrier for longer.

Yeah, the Lyman slugs don't fit very well in the Federal shotcups. Those shotcups are extremely thin and a uniform thickness all the way up. I am just opening the shells with a screwdriver to keep the crimp intact dumping out the birdshot and re-crimping them by re-folding that fold crimp. I actually don't have a press for fold crimps. I have a Russian hand crank roll crimping tool. I found that by applying pressure on the old fold crimp and rotating the roll crimping handle a couple of times I can actually get the fold crimps back into surprisingly decent shape (see photo below) It is super low tech and would generously be described as, frugal, I know, but seems to work okay.
242414

It was pretty hilarious when the range officer at my Public range came over to me last year and said, hey, you can't shoot bird-shot here on the 50 yard range and I showed him they were slugs. He was so confused for a second but they were cool with it.

I am shooting with a Mossberg 930 JM Pro with a Carlson's Rifled Choke Tube. Some people say rifled choke tubes don't do anything but in my experience they tighten up my groups (at least with this gun and these slugs) a bit. Obviously they aren't as good as a fully rifled barrel but those cost a lot more.

That (potential) flier is a real bummer. That group would have been sick without it. Just as good, if not better than the Truball and Slugger slugs. Anyway, I shouldn't get ahead of myself because one 5 shot or one 3 shot group doesn't prove anything but hopefully we will get similar results next time with more groups to show it wasn't a fluke.

Anyway, I just wanted to post where things stand now and also let you guys know I didn't blow myself up...Lol.

Don't worry about the thread drift, bows are interesting too. Maybe a 3d printed tail could help stabilize the slug through the trans-sonic region so it might be useful info.

[littlejack]

Mike, have you considered making one of the sabots with your 3-D printer in post #14, that would fit the Lyman slug? I think that may be a promising venture.
Littlejack

[mikehill85]

Another Update:

I fired about 20 round nose cap lyman 525 slugs and 20 wadcutter nose cap lyman slugs today. Below are representative 3 shot groups from today's outing with a round nose slug group first and a wadcutter slug group second. The round nose group is 1.3" center to center. The wadcutter group is 1.5" center to center. It appears to me that the round nose group has cleaner holes (this was generally the case). The wadcutter groups almost seem to show some signs of instability/keyholing. It may be that the round cap is actually improving the ballistic coefficient of the slugs, keeping them over the sound barrier longer. All shots are at 50 yards from a Caldwell Tackdriver rest. As in the last test, I am replacing birdshot in Walmart federal shells with the Lyman slugs and 3d printed skirts and caps to bring them up to bore diameter. The only difference between the groups is the shape of the cap (round nose or wadcutter). This week I didn't find an 3d printed parts on the way up to the target (just like last week) but I did find a lot of parts in the berm. I believe they are making it all the way to the target. Also please note that the reason the round nose group is so low is that my gun is sighted in for Winchester 1600 fps 1 oz slugs. These slugs are traveling about 1200 fps or slightly less. By the time I shot the wadcutter slugs I was adjusting for the drop by aiming at the very top of the target.

For my next test I will be trying to duplicate the Lightfield 2 part discarding sabot system.


Round Nose 3 Shot Group (Below)
242876

Wadcutter 3 Shot Group (Below)
242877

[mikehill85]

Mike, have you considered making one of the sabots with your 3-D printer in post #14, that would fit the Lyman slug? I think that may be a promising venture.
Littlejack

I haven't tried it yet. Now that I have tested the "skirt and cap" style I came up with I will try this. The one thing I am trying to determine with that design is what the purpose of the lead tabs on the side of the Lightfield slugs is and how I can replicate this with my 3d printed design. Any thoughts would be appreciated.

[longbow]

Looking pretty good I'd say! I am a bit surprised those caps stay on but you've got the fit sorted out and it works so that's good.

I am sure the tabs on the Lightfield are to ensure the wad gripping the rifling transfers spin to the slug (no skidding). I'd suggest knurling the Lyman slugs to roughen up the surface. If you don't have a knurler then just roll the slugs under a coarse file and that will raise the surface giving more grip to the wad. A good tight fit is probably good enough but roughing them up a bit certainly won't hurt... along with a tight fit.

On the 3D printed sabot, I was going to say just to make a tapered cylinder more or less replicating the wad petals of a trap wad because it is simple and works but... you have an opportunity to make a form fitting sabot that will support the skirt so no skirt collapse even with soft slugs. I think that has to be a benefit.

You should be able to easily print 2 or 3 piece sabots to form fit the slug and a bit oversize for groove diameter. I think I'd be inclined to make a 2 or 3 piece sabot that sits on top of a commercial trap wad cushion leg after cutting the petals off or buy the BPI brush wads (or equivalent) with no shotcup and sit your sabot on that. I think it is easier to do that than try to make a complete sabot with gas seal. But there I go taking over your project again!

This is interesting stuff! I wish I had a 3D printer and this just might get me into that game. You a potential enabler!

Longbow

[mikehill85]

Looking pretty good I'd say! I am a bit surprised those caps stay on but you've got the fit sorted out and it works so that's good.

I am sure the tabs on the Lightfield are to ensure the wad gripping the rifling transfers spin to the slug (no skidding). I'd suggest knurling the Lyman slugs to roughen up the surface. If you don't have a knurler then just roll the slugs under a coarse file and that will raise the surface giving more grip to the wad. A good tight fit is probably good enough but roughing them up a bit certainly won't hurt... along with a tight fit.

On the 3D printed sabot, I was going to say just to make a tapered cylinder more or less replicating the wad petals of a trap wad because it is simple and works but... you have an opportunity to make a form fitting sabot that will support the skirt so no skirt collapse even with soft slugs. I think that has to be a benefit.

You should be able to easily print 2 or 3 piece sabots to form fit the slug and a bit oversize for groove diameter. I think I'd be inclined to make a 2 or 3 piece sabot that sits on top of a commercial trap wad cushion leg after cutting the petals off or buy the BPI brush wads (or equivalent) with no shotcup and sit your sabot on that. I think it is easier to do that than try to make a complete sabot with gas seal. But there I go taking over your project again!

This is interesting stuff! I wish I had a 3D printer and this just might get me into that game. You a potential enabler!

Longbow

Quite honestly, I'm surprised they stayed on too. There are thousands of G of acceleration we are dealing with. I wish I had a high speed camera to see if the 3d printed parts are getting damaged in the barrel at all. My barrel was exceptionally clean this time around which would tend to indicate things are holding up nicely. I didn't see any lead streaking in the barrel at all. That said, the parts in the berm were quite shredded but then again the slugs are obviously horribly deformed upon impact and also dragging the skirt portion through a tunnel of dirt, so you can't tell much from that.

Please see below. As you can see the post that fills the cavity (truncated cone) broke off from the skirt but it well could be from going through the target and then boring a tunnel into the dirt/rock berm. The fact the skirt with a hole in it (where that truncated cone ripped out of the skirt) was found the berm too suggests as much. The nose on the slug also shows massive expansion (tough to show in photos but the front expanded from 0.68" to 0.975") so it isn't at all surprising that the ring on the nose caps (which bring the slug up to bore diameter) blew up and came off in the berm as well.

242891

This is the form fitting sabot so far. I flared the nose at the front to try to encourage the air pressure to slit the wad apart. Any thoughts/recommendations would be welcomed.

242893

BTW, do you have a link to those brush wads? That sounds like it might be an easy solution or in the worst case something to copy.

Re the friction fit, I think if I print the wad perpendicular to the direction of travel of the slug the print layers will naturally give the sabot some extra grip so maybe knurling isn't necessary for a good grip (assuming my tolerances are tight enough).

[littlejack]

Mike:
Personally, I don't think there will be any problem with the sabot breaking away. I believe that the air hitting the meplat (front) of the slug will separate the sabot just fine. If that's not enough for you, there's always that cyntrifical force thing. Lol

[longbow]

Brush wad:

https://www.ballisticproducts.com/Original-Brush-Wad-12ga-250_bag/productinfo/072BW12/

Other wads:

Stackable wads:

https://www.ballisticproducts.com/Gas-Seals/products/97/

That sabot is looking awfully nice!

Yes, if you have a tight fit knurling shouldn't be necessary. However, it wouldn't hurt to try rolling the slugs under a coarse file if there is any doubt or if accuracy isn't what you expect... just to be sure there is no slippage in the sabot.

You are making me want a 3D printer!

Longbow

[mikehill85]

Mike:
Personally, I don't think there will be any problem with the sabot breaking away. I believe that the air hitting the meplat (front) of the slug will separate the sabot just fine. If that's not enough for you, there's always that cyntrifical force thing. Lol

You are probably right. I will probably just print this guy and see how the fit is. It's hard for me to conceptualize supersonic ballistics but in the worst case, I do have a rifled choke tube so that should allow for separation as you pointed out.

[mikehill85]

Brush wad:

https://www.ballisticproducts.com/Original-Brush-Wad-12ga-250_bag/productinfo/072BW12/

Other wads:

Stackable wads:

https://www.ballisticproducts.com/Gas-Seals/products/97/

That sabot is looking awfully nice!

Yes, if you have a tight fit knurling shouldn't be necessary. However, it wouldn't hurt to try rolling the slugs under a coarse file if there is any doubt or if accuracy isn't what you expect... just to be sure there is no slippage in the sabot.

You are making me want a 3D printer!

Longbow

I'll see how the fit is but it's probably a good idea to roughen the surface on the 1st batch as you're suggesting and if things go well see if I can avoid it on the next batch (just to save some time).

I'm not sure if this is the case where you live in BC but I used to live in Ontario and a lot of the public libraries were starting to get 3d printers. You just needed to take a basic workshop on how to use them. No one reads anymore so they were trying to encourage people to come in. If it's an option it might be worth checking out. It is a blackhole of time in and of itself though. Lol.

FYI, Below is what one of the wadcutter skirt and cap slugs looks like in red Nylon.
242922

[littlejack]

Mike:
That skirt and cap looks really nice. I don't see any reason why it wouldn't work.
Very interested in seeing your 3-D sabot. And also the range report.
Regards

[mikehill85]

I finally got around to printing and testing the "lightfield" style sabot on the slugs this week. The results are pretty decent. Below shows part of the preparation and some 5 shot groups at 50 yards. Again, I was just using the el cheapo walmart Federal 8 shot birdshot shells, melting down the lead, casting Lyman slugs and using 3d printed parts to get a tighter fit in the barrel.

The bottom of the slugs with 3d printed filler

246271

The top of the slugs

246272

The slugs inside the shells

246273

Final roll crimped shell with slug

246274

A 2.52" 5 shot group.

246275

A 2.04" 5 shot group.

246276

[Roo59]

Well I thought the back would stay in place by the pressure at the back and the front would be forced in place by friction. I also planned on using steel wool to rough up the surfaces they are in contact with and super gluing them in place. With the extreme G forces it may not make any difference whatsoever but I thought I’d try it.

No need to use glue. there will be plenty of pressure to hold the cap and base in place. Years ago I used Winchester AA wads for 7/8 oz loads which had a dome to spread the shot pattern. The dome wedged into the base of the slug. They often did the trip together and accuracy was amazing out to 100 yards+.

[longbow]

Looking very good Mike! As in good looking slugs/sabots and groups reflecting that!

Is your HB filler glued it or loose?

Did you recover any slugs?

Did you recover any sabots? I'd be interested in seeing the recovered sabots.

Very impressive!

Longbow

[missionary5155]

This is all very encouraging ! Thank you for the photos included. It sure helps the mind to put it all together.

[mikehill85]

Thanks Longbow!

The day I went to test these was "free range day" so it was super packed and I didn't get a chance to try to recover the slugs. I did find pieces of the sabots and they were pretty fragmented I don't think this is very surprising, though, since they were all a short distance out in front of my shooting position and probably hit the ground at some speed. 3d prints tend to break along their layer lines since there is less of a bond in between individual layers than plastic molecules in the same layer. So they tend to be strong in compression but not so much in tension. It's also possible they broke up when going through my choke tube. In any case, whatever caused them to shatter didn't seem to hurt accuracy.


I did glue in the HB filler with some superglue and this seemed to keep the base attached to the slugs I recovered from the previous tests with the "cap and gown" style slugs. I don't know if this is really necessary but it helps when loading the slugs into the shells. If the HB falls out into the shell it is annoying to try to re-align it through an opaque shell.

Next up, I would like increase the velocity of the slugs and try the accuracy at longer ranges (100 yards). I'm not sure if this is possible with my cheap Walmart birdshot conversions though. Probably the safest way to do this would be to follow the recipes from the Lyman reloading data that came with the mold. Tests in a fully rifled barrel would also be interesting. If I can convince the wife to allow me it would be great to pick one up and see what kind of results I get.

Another awesome thing about these sabot slugs is that it doesn't leave lead in your barrel like Foster slugs. So you can basically just run a bore snake and you're good to go.

[mikehill85]

This is all very encouraging ! Thank you for the photos included. It sure helps the mind to put it all together.

Yes, I think I'm on the right track. It is only 50 yards but the results are quite good for a smoothbore shotgun and Walmart birdshot conversions.

[W.R.Buchanan]

Mike: I haven't followed this thread much but I see what you are doing, and it looks like you are making some good progress.

What is the OD of your nose and tail wads? Is your Smoothbore barrel Choked or Cylinder Bore?

Have you fired any of these in a Rifled Barrel?

These could easily be made on a lathe much faster than 3D printing, Have you considered that?

I can see excellent possibilities here with a rifled barrel. I have not been able to get these slugs to work at all from a Rifled Barrel using standard wads.

Randy.

[Blood Trail]

Mike: I haven't followed this thread much but I see what you are doing, and it looks like you are making some good progress.

What is the OD of your nose and tail wads? Is your Smoothbore barrel Choked or Cylinder Bore?

Have you fired any of these in a Rifled Barrel?

These could easily be made on a lathe much faster than 3D printing, Have you considered that?

I can see excellent possibilities here with a rifled barrel. I have not been able to get these slugs to work at all from a Rifled Barrel using standard wads.

Randy.

Randy,

I’ve had excellent results with the Lyman 525 using the following data from The Lyman 5th ed.:

STS hull
25 grs of Herco
Real WAA12 wad
Fold crimp

50 yard groups from my USH:

https://uploads.tapatalk-cdn.com/20191001/5a7fddf22b4d140da7f8f1ad12e74e28.jpg


Sent from my iPhone using Tapatalk

[W.R.Buchanan]

BT yes it appears that these work best from a Smoothbore. My A5 with the Buck Special Smoothbore Barrel shoots these pretty well and I need to get some pics of groups up.

Randy

[Blood Trail]

BT yes it appears that these work best from a Smoothbore. My A5 with the Buck Special Smoothbore Barrel shoots these pretty well and I need to get some pics of groups up.

Randy

That group was from a rifled barrel. Ultra Slug Hunter. [emoji2]


Sent from my iPhone using Tapatalk

[mikehill85]

Mike: I haven't followed this thread much but I see what you are doing, and it looks like you are making some good progress.

What is the OD of your nose and tail wads? Is your Smoothbore barrel Choked or Cylinder Bore?

Have you fired any of these in a Rifled Barrel?

These could easily be made on a lathe much faster than 3D printing, Have you considered that?

I can see excellent possibilities here with a rifled barrel. I have not been able to get these slugs to work at all from a Rifled Barrel using standard wads.

Randy.

Randy,

Apologies for the slow reply. I am not sure what the OD of the sabots were but I will check it tonight when I get home and let you know. I do recall they are a bit over 0.73".

I am shooting a Mossberg 930 with a 24" smoothbore with a Carlson's rifled choke tube. They seem to shoot best with the choke tube.

I definitely agree. I suspect these would shoot best out of a rifled barrel. I am a bit strapped for cash at the moment but in the future I would love to test the performance out of a rifled barrel. I think they have high accuracy potential with a bit of spin stabilization.

To me, the "Lightfield" design and "nose and tail wad" design seem to show comparable performance, however, the "nose and tail wad" system is simpler and uses less materials.

I hadn't considered doing this with a lathe but it is a good idea if you have one. Unfortunately I don't but as a lifelong tinkerer I'm sure I'll pick one up at some point.

[Hogtamer]

Went out last Thursday to get squared away till deer season. Wasn't going to post this because this was the best I ever shot my Lyman 525 and it seems like so much bee ess. But for what it's worth, 101 yd off piilow across hood of truck. Remington 870, Hastings 20" cantilevered barrel, Nikon slug hunter 3x9. Load was clear Fed multi-hull, nobel sport gtt1 wad, Fed 209a primer, 37 gr Longshot, Mp lyman clone cast from shrimp net weights (soft), cavity filled with hot glue and trimmed flush, clear frangible OS plastic card on top, 6 pt crimp. Wad petals shear off at firing. Blind hog finds acorn with this load but has killed 10-12 hogs. Shot 3" group with it last year so I guess it's the real deal.249506

[longbow]

Now that's not too shabby Hal! Not too shabby at all!

Its funny (strange funny) that some people get that slug to shoot and some don't.

Even though you've got a shooter there in gun and load you should get in on the Buckbuster clone group buy! A guy just can't have too many slug moulds can he? And we need a few more before it gets cut... hint, hint.

You can teach us how to load for it! You seem to have some magic tough!

Longbow

[Keith]

This is making interesting reading.
As about to embark on loading the Lyman slug for my C-More straight pull I was going to use the star crimp on existing hulls.
I see some use a roll crimp. I have an old roll crimp tool but was wondering how you get to it. Do you shorten star crimp hulls, as in cut the folded bit off somehow and just use the rolled bit?

[centershot]

This is making interesting reading.
As about to embark on loading the Lyman slug for my C-More straight pull I was going to use the star crimp on existing hulls.
I see some use a roll crimp. I have an old roll crimp tool but was wondering how you get to it. Do you shorten star crimp hulls, as in cut the folded bit off somehow and just use the rolled bit?

Aaahh, grasshopper, the wisdom you seek is found in a very special place........


http://castboolits.gunloads.com/showthread.php?372591-Lets-discuss-the-topic-of-Roll-Crimping-lots-to-here-need-to-get-it-all-in-one-place

[Keith]

Aaahh, grasshopper, the wisdom you seek is found in a very special place........


http://castboolits.gunloads.com/showthread.php?372591-Lets-discuss-the-topic-of-Roll-Crimping-lots-to-here-need-to-get-it-all-in-one-place

Woops. Thanks for that , I dont know how I missed it. Some reading there :)

[mikehill85]

BT yes it appears that these work best from a Smoothbore. My A5 with the Buck Special Smoothbore Barrel shoots these pretty well and I need to get some pics of groups up.

Randy

Randy,

The OD of the nose and tail wads are bang on 0.73".

[mikehill85]

Update:

I know I haven't done a great job of keeping this thread going but for those of you interested...I recently got a resin 3d printer which has a much higher dimensional accuracy than my old FDM printer. Although I can't really test the sabots at the moment please take a look at the results of the 3d printed sabots on a resin machine. The printer cost about $250 and makes parts that look like they were injection molded...unreal.
263519
263518

[ChuckJaxFL]

I hope we can resurrect this thread. I'd like to know what $250 printer produces results that look like that!

[Blood Trail]

Yes, we need any update!


Sent from my iPhone using Tapatalk

[littlejack]

Mike:
Wow, that looks great. Looking forward to seeing your range results.

[longbow]

That is looking good!

Yes... range report!?!

Longbow

[missionary5155]

That is a fine looking "package" ! Hard to beat a perfect fit.

[Cap'n Morgan]

Looks great! Perhaps they should be split in three 120 degree parts to ensure instant release when outside the muzzle?

[Mr_Sheesh]

I, too, really want to know the brand on that resin printer. Nice result!

[meadmkr]

I, too, really want to know the brand on that resin printer. Nice result!

Many resin printers will give that level of results. That is why so many people printing miniatures use them over a FDM filament printer. They are making strides with both the resin (smell, mess, cost) and the speed as well. There are resins now that can be cleaned off after printing with just water (vs acetone) and need minimal UV curing afterwards. Lots of discussion on various forums talking about printing components, sabots, 37mm and so forth. I'm still printing with PLA/PETG and haven't ventured into ABS and nylon due to the smell and additional tweaks to the printer.

Am following this thread to see where it goes. For now I'm redoing my reloading bench and safe so have been running my printer nearly 24x7 printing customized/color-coded organizers such as from
https://www.thingiverse.com/thing:3562433

[SuperBlazingSabots]

Greetings Mike, on your post #76 what resin did you use, how well did they hold?
If you were to buy another 3D Printer with what you know now, which one will you buy?
I have been watching Table model CNC too.

Sure would appreciate your feed back.

Best regards,
Ajay K. Madan
Super Blazing Sabots

[SuperBlazingSabots]

Good morning, here are some 3D printers
$679 https://www.amazon.com/dp/B00NA00MWS?tag=offersamzn-20&ascsubtag=bst-13-1693127501816072150
A bunch of some nice ones
https://www.amazon.com/Creality-Printer-Certified-Tempered-Extruder/dp/B07X3ZWTC7/ref=sr_1_1_sspa?dchild=1&keywords=3d%2Bprinter%2Bmodel%2Bender%2B5%2Bpricin g&qid=1614535183&sr=8-1-spons&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUFHRFY1VEJBVVQ5QlAmZ W5jcnlwdGVkSWQ9QTAzODc1OTcxRkwwUEdOMjhCSU1LJmVuY3J 5cHRlZEFkSWQ9QTA1NTY4NjYyUVRaWEFFTFhUMjRTJndpZGdld E5hbWU9c3BfYXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm9 0TG9nQ2xpY2s9dHJ1ZQ&th=1

XYZprinting - da Vinci mini w+ Wireless 3D Printer for $210

https://www.pcmag.com/picks/the-best-3d-printers

Sure would appreciate your feed back.

Best regards,
Ajay K. Madan
Super Blazing Sabots

[mikehill85]

Greetings Mike, on your post #76 what resin did you use, how well did they hold?
If you were to buy another 3D Printer with what you know now, which one will you buy?
I have been watching Table model CNC too.

Sure would appreciate your feed back.

Best regards,
Ajay K. Madan
Super Blazing Sabots

Very sorry for the slow reply. For that model I used Elgoo Grey Resin and I used an Elgoo Mars 3d printer. I haven't actually tested this iteration yet unfortunately, due to the pandemic and the general lack of ammunition. Which 3d printer I would get now depends on the application. If you want to 3d print things that are smaller and could benefit from an absurd level of detail (literally down to about 1/10 the thickness of a human hair), I would get a resin printer like the Elegoo Mars 2 or whichever similar printer happens to be on sale. The majority of these resin printers pretty much use the same design and same screen. Just make sure you get one that has a monochrome screen. They can print about 3 times faster than the color screen version.

If wanted a printer to print larger objects in a variety of materials, I would consider getting an FDM printer. There are many different versions you can choose from but just make sure to get one with an all-metal hot end that will let you print higher temperature materials. I have a Lulzbot Mini but they are expensive and I would recommend a budget option to start out with to see if you like it. If I were getting one now I'd probably look at that Prusa Mini or the Ender 3. The Ender 3 has a bigger print volume than the Mini but the Mini has self-leveling and a hot end with a higher maximum temperature (which means you can print higher temperature materials). I personally have Lulzbot Mini with a similar print volume to the mini and basically never find myself needing anything bigger but which you should chose if you go with FDM is dependent on your application. The Prusa Mini should do you for 95% of what you need. If you need to print something larger you can probably break it up into multiple parts and I think the ability to print more materials is worth the small difference in print volume. I would go with Prusa Mini+ if you're going with an FDM printer.

That being said, if you are just getting into 3d printing, the resin printers are hard to beat. The level of detail you can achieve with your prints is insane and far exceeds what you'll ever get on an FDM printer. They are also probably easier to use and give you results that you'll be happy with. A good resin print literally looks like it is injection molded as post #76 will attest to. Also resin printers are cheap, the resins are also relatively cheap now (and getting cheaper), and the resins are being offered with various properties now (and expanding in the range of material properties). I would personally recommend looking into something like an Elegoo Mars 2 with the monochrome screen. They are about $300 USD on Amazon now but you might be able to find something with the same specs (and pretty much the exact same printer) from a different brand for about $250. Just be aware that the $250-$300 resin printers only give you a print area of about the size of a large cellphone screen and the range of material properties of resin doesn't currently compare to FDM but I do think resin is the future of 3d printing for the most part due to the flawless print quality and dimensional accuracy you can achieve. You can get larger resin printers but they are about $900-$2,000.

If you or anyone else are interested in the 3d model files for this project I'd be happy to share them, including the Fusion360 source files which you could modify to your heart's content. I don't have a problem sharing with experienced reloaders but wouldn't post this design for the general public because they might get themselves hurt due to lack of reloading experience which as we know can be dangerous if not done properly.

Also, feel free to reply to my post here with any questions. I should respond fast now. I didn't know that I could link this thread to my e-mail and receive notifications when someone posts on this thread until now.

[mikehill85]

That is looking good!

Yes... range report!?!

Longbow

Sorry for the absurdly slow reply. I haven't been able to go out shooting because of the pandemic and general lack of ammo in the U.S. I haven't even seen 12 ga birdshot for some time now. As soon as I am able to I will share the results. I have been itching to test this out, believe me. The sabots fit like a glove!

[mikehill85]

Looks great! Perhaps they should be split in three 120 degree parts to ensure instant release when outside the muzzle?

That's a good idea. I was thinking that myself. Haven't had a chance to test this iteration yet unfortunately due to the pandemic and general lack of the ability to buy ammo in the U.S. but as soon as I do I will update the results here and consider this design if things don't go as planned. I think this will detach from the slug because I am shooting it out of a rifled choke but if it has trouble or the results are erratic I will certainly consider a 3-part sabot design.

[SuperBlazingSabots]

Good morning Mike, thanks for your reply. What resin was used for the post #76? Did you look for those two pieces after firing it and were they re-useable condition or shattered?

Sure do appreciate you reply, I just added to my card a $380 ANYCUBIC Photon S 3D Printer, UV LCD Resin Printer with Dual Z-axis Linear Rail and Upgraded UV Module & Print Quietly and Off-line Printing, Build Size 4.53"(L) x 2.56"(W) x 6.49"(H), Black
What says you?

Thank you.

Best regards,
Ajay K. Madan
Super Blazing Sabots

[mikehill85]

I say get something like the Elegoo Mars 2 with a Monochrome screen. It is about $80 cheaper and has a monochrome screen. Resin printers with a monochrome screen print about 3 times faster than ones with a color screen (like the Photon S). The resin I used is called "Elegoo Grey" from Elegoo. I haven't been able to test that sabot design yet but I suspect it will function fine but likely won't be reusable after. Not even regular shot cups are re-useable after firing.

https://www.amazon.com/ELEGOO-Photocuring-Monochrome-129x80x160mm-5-1x3-1x6-3inch/dp/B08F7L945C/ref=sr_1_5?dchild=1&keywords=elegoo+mars+2+pro&qid=1615133513&s=industrial&sr=1-5

[SuperBlazingSabots]

Hello Mike, I said that because for years I have been seeing those pieces at the range pretty much in good shape as they fly close-by being very very light.

I just added that ELEGOO Mars 2 Pro Mono MSLA 3D Printer UV Photocuring LCD Resin 3D Printer with 6.08 inch 2K Monochrome LCD, Printing Size 129x80x160mm/5.1x3.1x6.3inch to my cart its $300
Thank you.
Regards,
Ajay K. Madan
Super Blazing Sabots

[mikehill85]

Hello Mike, I said that because for years I have been seeing those pieces at the range pretty much in good shape as they fly close-by being very very light.

I just added that ELEGOO Mars 2 Pro Mono MSLA 3D Printer UV Photocuring LCD Resin 3D Printer with 6.08 inch 2K Monochrome LCD, Printing Size 129x80x160mm/5.1x3.1x6.3inch to my cart its $300
Thank you.
Regards,
Ajay K. Madan
Super Blazing Sabots

Nice. That's a sick printer. Wish I had waited about 9 months and gotten that one. It seems that right after I got my resin printer all the monochrome screen printers came out that print 3 times faster. Oh well. They are cheap enough that I can just get one with the monochrome screen too.

Yeah. I see what you're saying about those sabots. If you print in a high strength or flexible resin they might nearly be reusable too. I actually designed an airgun pellet and printed it in that Elegoo Grey Resin. To my surprise not only do the pellets survive firing but they completely embed themselves intact into a pine board. I clocked them at over 1800 fps out of a normal springer air rifle (a Crosman Phantom 1000). They are super loud too (for pellets) because they break the sound barrier. I tested them on clay blocks. Normal pellets will drill through the blocks leaving a nice clean path. These basically explode the clay on contact leaving a gaping crater and ejecting out a ton of clay. Anyway, I know this resin can survive being accelerated to 1,800+ fps in a relatively short distance so the sabot may well stay intact and be nearly reusable. I'll have to test them to see, which I can't wait to do.

https://www.thingiverse.com/thing:4458265

[mikehill85]

Update!

I went out shooting today with the two-part "Lightfield" style sabots. The results were less than stellar. The best 5 shot groups I got at 50 yards were about 3.5". See the full target below.

I was able to find some of the sabots. They appear to have traveled pretty far downrange (I found them around the 40 yard mark). The sabots did appear to have engaged the rifling in my rifled choke tube. I didn't recover any of the slugs. It rained last night and they were really buried in the soft dirt that makes up the backstop.

Next steps will be to try the shells without the rifled choke tube, to use a roll crimp instead of a star crimp, and printing a 3 part sabot which will hopefully release better. Some of the slugs hit the target going sideways. This leads me to believe that the sabots aren't separating consistently.

Any comments/suggestions are welcome.

Today's Target.
283661

Some finished shells with star crimp.
283662

Some recovered sabots with a fresh slug and a complete sabot half for comparison. There are marks from the rifled choke tube on the recovered sabot fragments.
283663

A 3 shot group.
283664

A 5 shot "group".
283665

An okay looking 5 shot group except for the wild sideways flyer in the upper right of the page.
283666

The best group of the day...4 shots touching blown up by a sideways flyer...
283667

[Cap'n Morgan]

Next steps will be to try the shells without the rifled choke tube, to use a roll crimp instead of a star crimp, and printing a 3 part sabot which will hopefully release better. Some of the slugs hit the target going sideways. This leads me to believe that the sabots aren't separating consistently.


I think the three part sabot is the way to go. Also, if room permits it, increase the diameter for a better grip/fit. Judging from the targets, the concept clearly has potential if you can eliminate the fliers. It could be the rifled choke is shifting slightly or the sabot not releasing smoothly enough. Probably the sabot, though.
BTW: What kind of sight are you using?

[mikehill85]

I think the three part sabot is the way to go. Also, if room permits it, increase the diameter for a better grip/fit. Judging from the targets, the concept clearly has potential if you can eliminate the fliers. It could be the rifled choke is shifting slightly or the sabot not releasing smoothly enough. Probably the sabot, though.
BTW: What kind of sight are you using?

Thanks for the advice. I think your idea in the first place was to use a 3 part sabot. I designed and printed some up yesterday. loading them in the shells it just "feels" better than the two part sabot in terms of potential to release properly from the slug. I've also used a roll crimp on these. I will be testing them out today to see if it helps. The nice thing is the range is basically a ghost town due to the fact ammo prices are still really high. Luckily 12 ga birdshot still costs about $22 for 100 shells, just like before the pandemic.

As for the sight, I have a Nikon Prostaff P3 Shotgun 3-9x40 scope. I'm mainly using it to take sight alignment out of the equation as much as possible.

Yeah, it seems like most of the slugs that left nice round holes landed fairly close together. The most painful group was the last one, 4 touching and 1 flyer (which was the last shot in the string)...Clearly not the fault of my aim that the slug flew into the target sideways but there are few things more painful than blowing up a nice group on the last shot.

[mikehill85]

Update 2:

I went shooting again today with the 3 piece sabot design and roll crimp. See results below (Please note all groups are 5 shot groups at 50 yards). I tried shooting with a cylinder bore choke instead of the rifled choke and the results were very poor so I switched back to the rifled choke.

I was able to recover 3 slugs and 2 sabots. One of the slugs which hit the target square on had the hollow base filler in the rear of the slug. Two that hit sideways had the base missing. It could have been dislodged on impact or maybe the base filler is partly to blame for the sideways flyers.

I feel like the results today were slightly better and I even got a pretty decent 2.8" 5 shot group. I'm very encouraged by the fact I got a decent group and seemed to have fewer sideways flyers.

Going forward I plan on:
1. Using hot glue for the hollow base, as some have suggested.
2. Replacing the notches on the sabots to index the sabot pieces relative to each other (I had removed them for simplicity and this may have been a mistake).
3. Printing the sabots in Nylon.
4. Increasing the diameter of the slug from 0.73" to something else. Any suggestions on a good diameter would be appreciated.

As always, any suggestions are welcome and appreciated.

Today's Target
283756

Group 1 (Note there are two slugs in the same hole near the bullseye)
283757

Group 2
283758

Group 3
283759

Group 4 (Note the crazy sideways flyer in the upper left.)
283760

Group 5 (2.8" Center-To-Center). This group didn't appear to have any flyers. I'd love to see more of this!
283761

The finished product with roll crimp
283762

The recovered sabot pieces and slugs
283763

[gpidaho]

As I have never 3D printed anything much less a shotgun sabot, I'll try not to be too helpful past the point of mentioning that I've fired powder coated paradox slugs.008 over bore constriction with no ill effect. You might try upping the diameter of the slug-sabot a bit at a time like working up a powder charge and see if the groups improve. Gp

[mikehill85]

As I have never 3D printed anything much less a shotgun sabot, I'll try not to be too helpful past the point of mentioning that I've fired powder coated paradox slugs.008 over bore constriction with no ill effect. You might try upping the diameter of the slug-sabot a bit at a time like working up a powder charge and see if the groups improve. Gp

Thanks for your advice. It is much appreciated.

[Cap'n Morgan]

I can't stress enough how important a strong and solid wad is for good results.
If possible, your sabot should match the cavity in the slug for best support, but the hot glue filler should work as well.
I ran into all kinds of trouble with my first injection molded wads - both the Brenneke clone and the sabot "Sleeve-Slug"

This is what the first sabots looked like after launch. The set-back had compressed the bottom to half the height:

https://i.imgur.com/5fnOgJF.jpg?1

This pic shows a recovered Brenneke taken apart. The indentions from the wad in the rim of the slug
vividly illustrates the forces involved during those critical first few milliseconds.
This wad was made from HDPE. (High Density Polypropylen) which is extremely tough.
Notice how the wad nose match the cavity in the slug for maximum support.

https://i.imgur.com/TsJBmKb.jpg?1

This is what a bunch of Brenneke looks like after being fired into a sand berm.
The one in front was shot through modified choke (notice the flattened ribs)
The rest were shot through a true cylinder barrel. (Diameter of both slug & wad is 0.73)

https://i.imgur.com/qs1QAZZ.jpg?2

And this is what it looks like when you finally get every thing in working order :wink:
This five shot group was shot at 64 yards from a smooth bore.

https://i.imgur.com/bw5j6sW.jpg?1

[mikehill85]

I can't stress enough how important a strong and solid wad is for good results.
If possible, your sabot should match the cavity in the slug for best support, but the hot glue filler should work as well.
I ran into all kinds of trouble with my first injection molded wads - both the Brenneke clone and the sabot "Sleeve-Slug"

This is what the first sabots looked like after launch. The set-back had compressed the bottom to half the height:

https://i.imgur.com/5fnOgJF.jpg?1

This pic shows a recovered Brenneke taken apart. The indentions from the wad in the rim of the slug
vividly illustrates the forces involved during those critical first few milliseconds.
This wad was made from HDPE. (High Density Polypropylen) which is extremely tough.
Notice how the wad nose match the cavity in the slug for maximum support.

https://i.imgur.com/TsJBmKb.jpg?1

This is what a bunch of Brenneke looks like after being fired into a sand berm.
The one in front was shot through modified choke (notice the flattened ribs)
The rest were shot through a true cylinder barrel. (Diameter of both slug & wad is 0.73)

https://i.imgur.com/qs1QAZZ.jpg?2

And this is what it looks like when you finally get every thing in working order :wink:
This five shot group was shot at 64 yards from a smooth bore.

https://i.imgur.com/bw5j6sW.jpg?1

Thanks for sharing. Thinking about the wads, I suspect I may know the reason for the poor release. The bottom part of the two part wad has a lip that sticks out at the bottom (see below). It may actually be grabbing onto the back of the sabot sections and also potentially sticking to the back of the slugs. I don’t remember seeing the bottom half of the two piece wad when I was checking for sabot pieces at the range. This could explain the crazy fliers. I have different shells which have one piece wads that I will try. Hopefully that will help.

283824

[mikehill85]

I had another thought. Maybe some of the slugs are tumbling because of their velocity. The theoretical muzzle velocity is about 1160 fps. According to information I found on the BC of this slug, at 50 yards the velocity should be about 1034 fps. Maybe it is destabilizing as it goes subsonic. I'm not sure how sensitive to velocity/going from transonic to subsonic this slug is but even variations in the velocities from slug to slug could potentially be causing some to start out subsonic and remain subsonic and others to start out above the speed of sound and drop below it in short order.

Anyway, I think I'll take my chronograph to the range next time and see what the actual muzzle velocity is and if there is any correlation between "flyers" and muzzle velocity.

Any thoughts on this would be appreciated.

[longbow]

I have no personal experience with this slug but turbo1889 (used to be a frequent poster here) maintained that the Lyman sabot slug became unstable at transonic velocity when shot from smoothbore.

True or not?

Longbow

[mikehill85]

Some better groups this last time out. I added a nitro card in between the slug and the bottom part of the 2-part wad and bumped up the sabot diameter by 0.008".

I recovered a couple of the original birdshot wads the slug rides on (shown below). At first I didn't even recognize them because they were flattened but based on these drastically improved results with the addition of the nitro card and the appearance of the wads I think the wad was actually grabbing the back of the sabot before and stopping them from separating properly.

For my next batch of slugs I will use Winchester AA wads with the pedals cut off. I think these may support the slug better.

Original Wad
284284

Wad After Firing
284285

All shots were taken at 50 yards. All groups are 5-shot groups except for the last "cloverleaf" group, which is 3 shots.

1.9" 5-shot group
284109

2.6" and 1.8" 5-shot groups
284110

0.8" 3-shot group
284111

[longbow]

That's looking better! In fact that's darn good!

Longbow

[mikehill85]

That's looking better! In fact that's darn good!

Longbow

If anything is wrong, it's probably my shooting. I've only been shooting since 2018. Yesterday there was a bit of a right to left crosswind too. Excuses aside, I'm happy with how things are starting to shape up.

[mikehill85]

I had one additional question I wanted to pose to anyone reading this thread with experience.

The last time I went out shooting I brought my chronograph. I only got about 10 shots off before an errant sabot piece hit the chronograph LCD and broke it. I have since purchased a replacement LCD which arrived today (it only took 2 days to get here from Poland and cost $13 total which is pretty amazing), I desoldered the old screen, replaced it with the new one and the chronograph is back in working order. I'm going to put acrylic guards in front of the screen and rear sensor before I go shooting with it next time.

My chronograph faux pas aside, I was getting very odd chronograph readings (~400-700 fps) and I'm wondering if anyone has any idea why. I'm thinking maybe muzzle blast was being picked up by the first sensor (in that case my chrony is too close to my muzzle). If it were picking up the wad, I believe my readings would skew on the high side.

[Cap'n Morgan]

Probably the muzzle blast - it will overtake the slug at the muzzle but quickly lose speed.
Increase the distance and aim high - it'll pick up those large slugs several feet, if not yards, above the chrony.

[mikehill85]

Thanks for the info. The fact it will pick up larger projectiles higher above the chrony makes sense. I will definitely shoot further above it next time I use it.

[mikehill85]

Update:

I went shooting today using shells with the Winchester AA12 wads as a base. The results were pretty decent I think (considering that I'm working with modified bird shot).

All groups are 5 shots at 50 yards

A 3.1" Group
284466

A 2.0" Group
284467

A 2.1" Group
284468

[longbow]

Mike:

That's looking pretty good!

However, something you might want to try to see if groups tighten up even more is to go to a plastic gas seal and hard card wad column or as Ranch Dog did all card wad column. Cushion legs crush and it is unlikely the base of the seal is dead square with the muzzle when they exit. We know what happens to cast boolits when bases aren't dead square with the muzzle so I have to think that a hard card wad column will provide better support and likely will remain more square in the bore and leaving the muzzle.

Link to Ranch Dog's post:

https://castboolits.gunloads.com/showthread.php?391840-Proofing-the-Lee-1-oz-without-Tail-Feathers

A consideration though is that if replacing the cushion leg with hard card wads I believe the reduction of volume at ignition (little crush compared to a cushion leg) that pressures rise. The effect seems more obvious with faster powders from the references I looked at. That would only apply if using a plastic gas seal to I think. Ranch Dog went with all card wads and from my experience there is a lot of blow by using all card wads so that should negate any pressure rise.

Anyway, using a hard card wad column for consistent support and square to muzzle base and a hull that fills the chamber might tighten groups up even more.

I have some slugs in shotcups with cushion leg cut off loaded over hard card wad column now. Just have to get some time to go shooting.

Longbow

[mikehill85]

Mike:

That's looking pretty good!

However, something you might want to try to see if groups tighten up even more is to go to a plastic gas seal and hard card wad column or as Ranch Dog did all card wad column. Cushion legs crush and it is unlikely the base of the seal is dead square with the muzzle when they exit. We know what happens to cast boolits when bases aren't dead square with the muzzle so I have to think that a hard card wad column will provide better support and likely will remain more square in the bore and leaving the muzzle.

Link to Ranch Dog's post:

https://castboolits.gunloads.com/showthread.php?391840-Proofing-the-Lee-1-oz-without-Tail-Feathers

A consideration though is that if replacing the cushion leg with hard card wads I believe the reduction of volume at ignition (little crush compared to a cushion leg) that pressures rise. The effect seems more obvious with faster powders from the references I looked at. That would only apply if using a plastic gas seal to I think. Ranch Dog went with all card wads and from my experience there is a lot of blow by using all card wads so that should negate any pressure rise.

Anyway, using a hard card wad column for consistent support and square to muzzle base and a hull that fills the chamber might tighten groups up even more.

I have some slugs in shotcups with cushion leg cut off loaded over hard card wad column now. Just have to get some time to go shooting.

Longbow

I gave that idea a try, using only nitro cards instead of repurposing the original wad. Keyhole City today. To add insult to injury I found that my scope slid back in the rings...So there's nothing here even resembling a group. Let me know if it works out any better for you.

As a side note, the shells didn't reliably cycle in my semi-auto shotgun. I think this supports the idea that nitro-cards allow more blow by than gas seals.

It was well worth a try, in any case.

284799

[mikehill85]

I got a new slug mould from Russia (the Svarog "Paradox" slug). It seems the wads are unobtainium so I have designed my own tail wad which repurposes the gas check from the Federal Two Part wad that came with the shells I bought. The tail wad is permanently attached to the slug with a wood screw through the end. I can't wait to test this bad boy out. It is bore diameter too so it should hopefully be accurate.

285093

285095

[longbow]

I think Blood Trail has that mould. You might do a search of his posts.

Kracken69 sent me some to try. They shot reasonably well from my single shot but are a bit undersize in the 0.733" bore.

Now I have the Mossberg Slugster with 0.729" bore. I have a few left so have to try them in the tighter bore.

I think you'll like them!

I'll be watching for a range report.

Longbow

[mikehill85]

Interesting. My shotgun also has a 0.733” bore diameter. Hopefully my rifled choke will help a bit. If not I guess I can try powder coating them.

[longbow]

Knurling will bring them up in diameter. I knurled some that Krackenfan69 sent but again, have not shot them in my single shot... they're loaded and waiting for me! Knurling takes them up to 0.735" or so, so they will have to swage to fit the bore.

I will try the knurled up slugs in the single shot and as supplied at 0.729" IIRC in my Slugster with 0.729"/0.730" bore.

Hoping to get out next week. I will post results and will be looking forward to your results as well.

Longbow

[mikehill85]

Knurling will bring them up in diameter. I knurled some that Krackenfan69 sent but again, have not shot them in my single shot... they're loaded and waiting for me! Knurling takes them up to 0.735" or so, so they will have to swage to fit the bore.

I will try the knurled up slugs in the single shot and as supplied at 0.729" IIRC in my Slugster with 0.729"/0.730" bore.

Hoping to get out next week. I will post results and will be looking forward to your results as well.

Longbow

Same here. I'll be interested to see your results. I should be going out shooting mine tomorrow.

I'm really enjoying the range these days. There are far fewer people due to the ammo shortage and most who are there are shooting 0.22s not AR-15s with the shortest barrel legally possible and a muzzle brake designed to shatter eardrums.

[mikehill85]

Update:

I had considered not posting this because quite frankly I am embarrassed and upset with myself but I thought I would anyway so hopefully others can learn from my mistake.

Well that was bad...I'm okay. My gun is okay and so is everyone else but I'm pretty pissed at myself. I guess I got too complacent with reloading. I figured that since this slug weighed nearly the same as the Lyman 525 Slugs I wouldn't have pressure issues. After I fired 5 shots I noted just the brass portion of one of the shells was extracted. I should have been checking all along and I'm posting this so others will know what not to do. If I had fired 1 shot, noticed the over pressure signs and stopped, I could live with that. That can happen if you're experimenting (although it's obviously still very bad), but the fact I fired 4 more before I noticed is really bad. Everything sounded fine, felt fine, etc., but I should have been checking for over pressure after every shot.

Weighing the slugs afterwards I found that with my 3d printed base wad the weight of the payload increased from 568 grains to 612 grains. I think this and the fact the 3d printed Nylon may not compress as much as LPDE is what lead to the obvious over pressure signs I got. I think not taking into account the weight of the wad was my biggest mistake. Anyway, lesson learned. I won't be using 3d printed wads for these slugs.

The fact myself and my gun weren't damaged hasn't been lost on me and I am grateful for that.

BE SMART! I WAS DUMB! DON'T DO THIS! DON'T BE COMPLACENT!

285276

Clear Primer Cratering and Extractor Groove Extrusion. Yikes!
285277

Several hulls are torn...One is missing everything but the brass. Yikes again!
285278

The next two photos give you an idea just how raised the extractor mark is.

285295

285296

[longbow]

I've always gotten sticky extraction with over pressure loads... and yes it has happened more than once!

I am pretty carefull but sometimes things don't go quite as planned or expected.

The bulge into the extractor groove and sticky extraction are I think the first signs of over pressure and I believe that a load that does either is significantly over pressure.

The other is unexpectedly stout recoil!

Good that you and the gun are okay.

Longbow

[mikehill85]

I'm pretty surprised that an 8% increase in weight could increase the pressure so drastically. I never had any pressure signs like this before and they appear to be pretty extreme based on the shells and brass.

I am wondering if perhaps it is the fact that my wad went all the way up into the cavity of the slug where the lead is thin. Maybe when it fired the Nylon wad was pushed into the nose and caused the slug to obturate. That could certainly cause a very significant spike in pressure.

Anyway, this is the first time I've tried using a Nylon wad. I think the material/wad design may have had more to do with the pressure spike than the increase in weight. Obviously increasing the weight will increase the peak pressure but it seems to me the weight increase alone might not explain this level of pressure increase.

I actually found one of the slugs at the target with the tail wad still attached. It had the layer lines from the 3d print etched into it which might support the idea that the wad actually caused the slug to obturate. It was a bit hard to tell too much from the slug since it was pretty mangled but the holes in the target were circular so it was definitely mangled on impact.

[longbow]

In case you missed it, I have posted several times about my experience blowing up a shotgun, Not fun!

A short version of the story is that I loaded short rounds with a Lyman Foster slug with filled cavity. The slugs were cast from pure lead per Lyman instructions, the load was straight out of the Lyman reloading manual with the exception of short hull and filled slug. I only had one powder on hand and that was PB per recipe.

I had shot a few of these in my Browning BPS and recoil was particularly attention getting and extraction sticky but since it was a book load I just figured it was a "stout" load.

Next outing I took my single shot shotgun, bore was clear and easily observable being single shot, dropped a round in, took aim and pulled the trigger... there was a very loud explosion, blast of debris in my face and the gun went "limp"! When I recovered after a few seconds I found myself holding the action and buttstock in my right hand and forearm in my left hand. The barrel was laying on the ground about 10' in front of me with the entire top of the chamber missing!

Later examination showed lead streaks from where the case mouth was up to the forcing cone. My take is that the soft filled slug was obturating as it left (or maybe in) the hull then hit the forcing cone and just couldn't swage back down fast enough so pressure spiked. The BPS survived several shots seemingly unaffected but the single shot only took one round to destroy it.

I don't believe it was a fault in the gun because I should have paid attention to the punishing recoil and sticky extraction but at the time was not smart enough to see the over pressure signs.-- or at least respond appropriately to the over pressure signs.

I was very lucky and just got some minor cuts on my forehead and I lost about 40 decibels of hearing in my right ear... I was in the bush and like when hunting did not have shooting glasses or hearing protection. Stupid! And lucky! I am more careful now and I am very careful when working on slug loads substituting components. I make minimal subs and use low pressure data so there is a margin for error if pressures go up for some reason not evident to me.

Considering that a simple change of primer can affect pressure by up to 3000 PSI and crimp depth can have a similar effect, it is pretty easy to take a top end load over the top into dangerous territory with not much change in load/payload.

Okay not such a short story but worth repeating if it saves someone else's gun and/or body parts!

Play but play safe!

Longbow

[mikehill85]

In case you missed it, I have posted several times about my experience blowing up a shotgun, Not fun!

A short version of the story is that I loaded short rounds with a Lyman Foster slug with filled cavity. The slugs were cast from pure lead per Lyman instructions, the load was straight out of the Lyman reloading manual with the exception of short hull and filled slug. I only had one powder on hand and that was PB per recipe.

I had shot a few of these in my Browning BPS and recoil was particularly attention getting and extraction sticky but since it was a book load I just figured it was a "stout" load.

Next outing I took my single shot shotgun, bore was clear and easily observable being single shot, dropped a round in, took aim and pulled the trigger... there was a very loud explosion, blast of debris in my face and the gun went "limp"! When I recovered after a few seconds I found myself holding the action and buttstock in my right hand and forearm in my left hand. The barrel was laying on the ground about 10' in front of me with the entire top of the chamber missing!

Later examination showed lead streaks from where the case mouth was up to the forcing cone. My take is that the soft filled slug was obturating as it left (or maybe in) the hull then hit the forcing cone and just couldn't swage back down fast enough so pressure spiked. The BPS survived several shots seemingly unaffected but the single shot only took one round to destroy it.

I don't believe it was a fault in the gun because I should have paid attention to the punishing recoil and sticky extraction but at the time was not smart enough to see the over pressure signs.-- or at least respond appropriately to the over pressure signs.

I was very lucky and just got some minor cuts on my forehead and I lost about 40 decibels of hearing in my right ear... I was in the bush and like when hunting did not have shooting glasses or hearing protection. Stupid! And lucky! I am more careful now and I am very careful when working on slug loads substituting components. I make minimal subs and use low pressure data so there is a margin for error if pressures go up for some reason not evident to me.

Considering that a simple change of primer can affect pressure by up to 3000 PSI and crimp depth can have a similar effect, it is pretty easy to take a top end load over the top into dangerous territory with not much change in load/payload.

Okay not such a short story but worth repeating if it saves someone else's gun and/or body parts!

Play but play safe!

Longbow

No, I hadn't heard about this incident. Thanks so much for sharing. I'm glad you were okay. It definitely sounds like your slug may have obturated. I think from now on I may just fill the hollow base with hot glue which probably isn't hard enough to obturate the slug. Come to think of it, I also noticed lead streaks all the way along my barrel (which may be somewhat expected since this slug is nearly bore diameter but they were all the way along the barrel on the top and bottom so it would seem to support the idea the slug probably obturated.

Thinking about your note on crimp length, I also used a roll crimp which was longer than usual. In hindsight, I had a heavier payload, a hard plastic likely to obturate the slug (since the cavity is shaped like a cone it would actually be surprising if it didn't obturate), and a longer crimp. So I made a lot of mistakes (which is usually the way things end up going badly wrong).

In any case, this was the best type of incident that could happen. No one got hurt and it has jolted me out of complacency. Dangerous things are dangerous it turns out...Hopefully people can learn from this and avoid my mistakes.

[longbow]

If you haven't seen this it is an informative read:

http://www.armbrust.acf2.org/primersubs.htm

and this:

https://www.hodgdonreloading.com/effect-crimp-depth-shotshells

So, imagine that you picked a recipe that generating 10,500 PSI and you subbed a "hot" primer and you crimped extra deep and the payload was 5% to maybe 10% heavier. Any one of those could raise pressure to SAAMI max and a combination could put you well over SAAMI max.

Having said that, it seems to be the general opinion that modern shotguns are much overbuilt, but still, it deserves attention to details and conforming within reasonable limits or you risk a serious incident. As I said, my Browning BPS seems none the worse for wear after having some quite sticky extraction with those loads mentioned but Browning guns are reputed to be "well built" and likely could be rated to higher pressure, but a gun that just meets SAAMI specs is a different animal altogether!

Having experimented with hot melt glue, I can say that it does expand under pressure. I have used and am still using hot melt glue for attached tailwads and when a wad slug that is barely snug in the shotcup/barrel is fired with the hot melt glue tailwad, it is evident on the shotcup petals that the hot melt glue has expanded to squeeze the petals. Whether that translates into expanding a hollow base slug I can't say for sure and especially if the glue is fully in the cavity and slug skirt sitting on the wad column... in that case.

After my incident I have been careful of using hollow base slugs in short hulls in 3" chambers and filling cavities. I am quite sure the premature obturation in the chamber then resistance to swaging back at the forcing cone is primarily what caused the blow up of my gun. I do not recall details of primer and crimp so considering the above documents that may also have come into play.

Longbow

[mikehill85]

Very interesting stuff. Thanks for sharing. I will definitely be very careful about crimp length, payload weight, and hollow base fillers (and component substitution in general) from now on.

I honestly think the only reason I didn't end up with a really big problem is that modern shotguns are "overbuilt" like you say (not that you should count on that). I've read on some forums that shotgun shells don't show any signs of overpressure. It's very possible this used to be the case but at least in my case I was lucky enough that my shotgun was able to take the pressure and spit only the brass part of the hull out onto my shooting bench at which point I thought "Holy S**t!".

[mikehill85]

FYI,

I double checked my bore and I have lead deposits in my bore leading up to the forcing cone. See below photo (the white circle). It seems the slug almost certainly obturated. Yikes!

285322

[longbow]

Yeah, I am not sure if it matters or not but my blow up I attribute largely to a filled slug obturating to full the chamber if not the hull, then slamming into the forcing cone. That it happened is not in doubt as the lead streaks showed it did happen. Was that the sole cause of the blow up? Was it because the slug was filled?

My understanding of the Lyman Foster slug is that it does obturate to fill the bore and I know for a fact it does get shorter and fatter after firing than it was before firing as I have collected them from soft snow after shooting and they are shorter and fatter matching the bore diameter where they start out at 0.705" diameter. However, unfilled they may obturate then swage back easily so not an issue.

I guess the only way to determine any effect of filler or type of filler would be to load an unfilled slug then then shoot and record pressure then repeat with slugs filled with a variety of "fillers" like hot melt glue, silicone caulk, wax, cornmeal, heavy grease, or whatever people have used, with nothing else changed.

I have made forms to put the slug into then filled hollow cavity and extend into the form with hot melt glue to make a tailwad. I know that glue tailwad does expand under pressure because the shotcup petals show compression where that glue tailwad squeezes them. These have been wad slugs of course and all cast from ACWW or range scrap so harder than pure lead.

I have not seen signs of over pressure with these but wonder if the HB cavity being filled could possibly lead to the same obturation in chamber then pressure spike at forcing cone. Since the slugs have been harder lead than the Lyman Fosters that were showing sticky extraction I am not sure if they were cast softer would that be a problem? Since the filler is elastic, maybe?

My current tack is to use screwed on tailwads so the cavity isn't filled leaving the HB slug to respond as it normally would to a choke of whatever. I don't think an elastic tailwad sitting behind the slug is an issue as it can freely compress. When that same elastic material is acting hydraulically under compression of powder gasses inside a hollow cavity I am not so sure how the filled slug responds to a constriction. Things happen in milliseconds in a gun barrel.

Point here being is that your nylon filled slug may be obturating due to the hydraulic reaction of compressed nylon and not able to squeeze down fast enough to avoid a pressure spike.

It is all a bit of speculation on my part but I want to keep things safe so will err on the side of safety. One blow up was enough!

Longbow

[mikehill85]

I agree. Better the err on the side of caution. Check out the below photos of one of the recovered slugs. All the ridges are completely flattened all the way around the slug (probably from obturating in the barrel) and the layer lines of the print are clearly etched into the interior. The slug completely burst open from the nose down. Accuracy was atrocious. I assume this was caused by the tail wads not holding up.


Flattened Ridges
285378

More Flattened Ridges on the Other Side
285379

3d Print Layer Lines
285380

The Recovered Slug
285381

[longbow]

Having looked more closely at your nylon tailwad I have another couple of comments...

The original style wads don't fill the hollow base, They have a post that slips over a pillar cast in the slug. By filling the cavity the nylon may be hydraulically swaging the slug skirt against the bore creating high bore friction and explaining the swaged to non-existence grooves.

Not sure how much the nylon tailwad collapses under pressure. I notice that you have used a design similar to the Gualandi style cushion leg but... I believe that when a cushion leg is removed from a recipe calling for one that pressure spikes due to less volume at ignition (lack of cushion collapse). This is my opinion based on some results I got and comparing short hull loads (no cushion leg) with regular loads using cushion leg. Also, from what I interpret the effect seems to be less of an issue with slow powders than fast powders which makes sense.

I have no proof of this but some loads I put together where I removed the cushion leg wad and used a solid wad column, with no other changes, and got sticky extraction I decided to do some cross referencing and came to the conclusion that it at least makes sense that by removing the cushion leg there is less volume at ignition so pressure may peak sooner. Just another one of those little variables that can affect pressure.

So, if the nylon tailwad is hydraulically swaging the slug skirt against the bore and the "cushion" on your wad is stiff that could easily explain the results you are getting.

It would be nice to do some pressure testing to check the effect of cushion leg or lack of for comparison.

Not sure how much testing would be required but at least 5 rounds each using cushion leg and again with solid wad column for a fast powder and of a slow powder to check. That would be 20 rounds using just two powders. I wonder if we could talk Blood Trail into doing it? I'd help finance the testing with supplies or cash.

Longbow

[Cap'n Morgan]

In case you missed it, I have posted several times about my experience blowing up a shotgun, Not fun!

Since you mentioned blow-ups I might as well relate an experience of my own. Although it happened with a rifle, it has some similarity to your mishap
(and MegaMag's S.E.E "myth" :wink:)

Back in the late seventies i bought a Swedish M96 rifle. Later I also bought several hundreds 156 grains 6.5x55 Danish mill surplus ammo
(M96 was our military rifle for a few years after the war) The rifle appeared brand new, and I doubt it had ever been used, much less fired.

Well, I enjoyed the rifle and shot it from time to time. Then one day while studying my "bible", The Book of Rifles, I came across a warning
in a chapter of Swedish rifles. It mentioned a specific lot of Danish mill surplus ammo in 6.5x55 which had caused several blow-ups on Danish shooting ranges.
The headstamp was clearly described, and (you guessed it) it matched my cartridges!

That gave me something to think about, I wasn't rolling in money at that time and didn't fell like scrapping the lot.
The book said the problem was caused by fouling due to too the jackets being too soft, and I decided to try to reduce the load a little and maybe avoid fouling.
I pulled the bullets from four cartridges, weighed the powder and loaded the cartridges again with a 10% reduced load (weighing each load on my Ohaus 1010)
and, together with a couple of friends, went to test the load.

The first two rounds fired as expected, and I remember telling my pals that the load seemed quite mild for a 10% reduction. Then I fired the third round...

I can't remember hearing any boom, but I remember distinctly the feeling of warm blood running down my nose.

To make a long story short, here's what had happened: The bullet never left the barrel. It was lodged firmly in the throat of the chamber with the rear of
the bullet deformed and expanded (I later tapped the bullet out from the front without using much force) Since the pressure had nowhere to go, it went
out the rear of the case, into the firing pin hole and blew the firing pin rearwards with such a force that the 1/4" pin snapped and the rear part flew back
hitting the knuckle on my thumb (four stitches) then hitting right between my eyebrows (two stitches) before taking off for places unknown.

After a visit to the emergency room, and a cock-and-bull story about a bench drill job gone wrong, I was non the worse for wear, but a little shaken...

When I later examined the rifle, it was obvious that the reason the blow-back had such a disastrous result was the vent holes in the M96 bolt were too small,
compared to the two large slots in a M98 bolt it's obvious that Mauser learned something between model 96 and 98.
I replaced the parts in the bolt, including the mainspring that was reduced to half length, "sporterized" the rifle, and continued to use it for hunting for the next
twenty years (and I enlarged those vent holes!)

I'm not quite sure what happened that day back then. But I'm sure it was the same thing that had happened on the other Danish shooting ranges, and by reducing
the loads I had actually increased the likelihood for the blow-back to happen.

[Blood Trail]

As reloaders, we tend to forget about how slug columns affect pressure: hard verses soft launch.

When I sent Uncle D’s 580 gr Fury slugs to be tested before I purchased my Pressure Trace 2, I sent five loads off. Two of those were with 38 grs of Blue Dot with a hard finer wad stack up and the other was with 40 grams of steel sitting on a brush wad.

Surprisingly enough, the steel load came in around 7.5-8k psi while the Blue Dot load was around 11k psi. I know that you get more velocity on a lower pressure curve with steel than Blue Dot but I didn’t think it would be that drastic. The crush section really helped tame pressure.

From my testing with my pressure trace 2, looks like your loads were 20k psi or higher.

Good thing is, most modern shotguns are overbuilt. Tom Roster was hired by Remington to test their 870 barrels to failure. They didn’t blow until 55k psi.


Sent from my iPhone using Tapatalk

[mikehill85]

Having looked more closely at your nylon tailwad I have another couple of comments...

The original style wads don't fill the hollow base, They have a post that slips over a pillar cast in the slug. By filling the cavity the nylon may be hydraulically swaging the slug skirt against the bore creating high bore friction and explaining the swaged to non-existence grooves.

Not sure how much the nylon tailwad collapses under pressure. I notice that you have used a design similar to the Gualandi style cushion leg but... I believe that when a cushion leg is removed from a recipe calling for one that pressure spikes due to less volume at ignition (lack of cushion collapse). This is my opinion based on some results I got and comparing short hull loads (no cushion leg) with regular loads using cushion leg. Also, from what I interpret the effect seems to be less of an issue with slow powders than fast powders which makes sense.

I have no proof of this but some loads I put together where I removed the cushion leg wad and used a solid wad column, with no other changes, and got sticky extraction I decided to do some cross referencing and came to the conclusion that it at least makes sense that by removing the cushion leg there is less volume at ignition so pressure may peak sooner. Just another one of those little variables that can affect pressure.

So, if the nylon tailwad is hydraulically swaging the slug skirt against the bore and the "cushion" on your wad is stiff that could easily explain the results you are getting.

It would be nice to do some pressure testing to check the effect of cushion leg or lack of for comparison.

Not sure how much testing would be required but at least 5 rounds each using cushion leg and again with solid wad column for a fast powder and of a slow powder to check. That would be 20 rounds using just two powders. I wonder if we could talk Blood Trail into doing it? I'd help finance the testing with supplies or cash.

Longbow

Yes, it would be very interesting to see how wad cushioning affects pressure. Based on my qualitative examination of Nylon vs the materials that factory wads are made of I would say Nylon is much harder and definitely wouldn't provide as much cushioning.

I was trying to choose a material I thought could survive being fired in one piece and although it seems it more or less accomplished that I do think the lack of cushioning is one of the major contributors to the pressure spike (probably along with swaging the slug in the chamber). If you look at a lot of more modern mechanical devices with injection molded plastic parts you'll find a lot of times gears are made of Nylon (because it is tough and self-lubricating). I was thinking of using something like TPU/TPE but I think that might be too flexible. That has more or less the properties of rubber.

In any case, I have decided to try shooting this slug again using hot glue as a filler, two nitro cards under the slug, and an FS12 gas seal on the bottom. I believe that this will not result in pressure spikes. The FS12 gas seal should provide cushioning and the payload isn't any heavier than the Lyman 525 payload which had no pressure signs (and I've fire 100s of such slugs without incident...In some cases completely replacing the original wad with nitro cards...). This time I will definitely be checking the shells for pressure signs every step of the way.

[mikehill85]

Since you mentioned blow-ups I might as well relate an experience of my own. Although it happened with a rifle, it has some similarity to your mishap
(and MegaMag's S.E.E "myth" :wink:)

Back in the late seventies i bought a Swedish M96 rifle. Later I also bought several hundreds 156 grains 6.5x55 Danish mill surplus ammo
(M96 was our military rifle for a few years after the war) The rifle appeared brand new, and I doubt it had ever been used, much less fired.

Well, I enjoyed the rifle and shot it from time to time. Then one day while studying my "bible", The Book of Rifles, I came across a warning
in a chapter of Swedish rifles. It mentioned a specific lot of Danish mill surplus ammo in 6.5x55 which had caused several blow-ups on Danish shooting ranges.
The headstamp was clearly described, and (you guessed it) it matched my cartridges!

That gave me something to think about, I wasn't rolling in money at that time and didn't fell like scrapping the lot.
The book said the problem was caused by fouling due to too the jackets being too soft, and I decided to try to reduce the load a little and maybe avoid fouling.
I pulled the bullets from four cartridges, weighed the powder and loaded the cartridges again with a 10% reduced load (weighing each load on my Ohaus 1010)
and, together with a couple of friends, went to test the load.

The first two rounds fired as expected, and I remember telling my pals that the load seemed quite mild for a 10% reduction. Then I fired the third round...

I can't remember hearing any boom, but I remember distinctly the feeling of warm blood running down my nose.

To make a long story short, here's what had happened: The bullet never left the barrel. It was lodged firmly in the throat of the chamber with the rear of
the bullet deformed and expanded (I later tapped the bullet out from the front without using much force) Since the pressure had nowhere to go, it went
out the rear of the case, into the firing pin hole and blew the firing pin rearwards with such a force that the 1/4" pin snapped and the rear part flew back
hitting the knuckle on my thumb (four stitches) then hitting right between my eyebrows (two stitches) before taking off for places unknown.

After a visit to the emergency room, and a cock-and-bull story about a bench drill job gone wrong, I was non the worse for wear, but a little shaken...

When I later examined the rifle, it was obvious that the reason the blow-back had such a disastrous result was the vent holes in the M96 bolt were too small,
compared to the two large slots in a M98 bolt it's obvious that Mauser learned something between model 96 and 98.
I replaced the parts in the bolt, including the mainspring that was reduced to half length, "sporterized" the rifle, and continued to use it for hunting for the next
twenty years (and I enlarged those vent holes!)

I'm not quite sure what happened that day back then. But I'm sure it was the same thing that had happened on the other Danish shooting ranges, and by reducing
the loads I had actually increased the likelihood for the blow-back to happen.

Thanks for sharing. Glad you were okay. It is funny that sometimes the very measures we take to prevent something from happening actually cause that thing to happen/make it worse.

[mikehill85]

As reloaders, we tend to forget about how slug colons affect pressure: hard verses soft launch.

When I sent Uncle D’s 580 gr Fury slugs to be tested before I purchased my Pressure Trace 2, I sent five loads off. Two of those were with 38 grs of Blue Dot with a hard finer wad stack up and the other was with 40 grams of steel sitting on a brush wad.

Surprisingly enough, the steel load came in around 7.5-8k psi while the Blue Dot load was around 11k psi. I know that you get more velocity on a lower pressure curve with steel than Blue Dot but I didn’t think it would be that drastic. The crush section really helped tame pressure.

From my testing with my pressure trace 2, looks like your loads were 20k psi or higher.

Good thing is, most modern shotguns are overbuilt. Tom Roster was hired by Remington to test their 870 barrels to failure. They didn’t blow until 55k psi.


Sent from my iPhone using Tapatalk

Interesting. It makes sense it would have to be considerably over SAAMI spec pressure. Like you said, it's definitely a good thing that modern shotguns are overbuilt. Otherwise I'm pretty sure I'd at least be looking at replacing the shotgun (if not some fingers). I checked the barrel and everything is totally fine. There's not so much as a nick on the bolt lock either so it survived it shockingly well.

One thing I was wondering about was how the entire plastic portion of the shell was ripped off of the brass (which is the first thing I noticed that threw up huge alarm bells for me). I guess the pressure must have built before the roll crimp was able to unravel and just created a crazy slug cut shell. Lol. It's also interesting how some of them are torn. Maybe that's because the slug expanded in the chamber and literally just ripped parts of the shell out and took them with it.

[Frosty Boolit]

Mike, I thought of something cool when I saw your original printing capability. What if you printed an aerodynamic slug that just had a hole along its axis that stopped short about 1/4" from the bottom and maybe it's .456" diameter so a 45/70 405gr boolits fits snug in it. Then you'd have a "sabot" that's actually the bullet too, with the lead boolit providing the weight that the plastic doesn't.

[mikehill85]

Mike, I thought of something cool when I saw your original printing capability. What if you printed an aerodynamic slug that just had a hole along its axis that stopped short about 1/4" from the bottom and maybe it's .456" diameter so a 45/70 405gr boolits fits snug in it. Then you'd have a "sabot" that's actually the bullet too, with the lead boolit providing the weight that the plastic doesn't.

That's an interesting idea. It should theoretically work. The center of mass will be up towards the nose. I'd just have to design a tail to move the center of pressure to the back. Wasp-waisted designs (like a giant airgun pellet) tend to seem to work well.

[mikehill85]

I tested out the Svarog slugs again using two nitro cards on a FS12 gas seal. I saw pressure signs again. These weren't as bad as last time where I got torn shells but I could still see primer cratering and extractor marks.

I tried the same thing with the Lyman 525 slug (two nitro cards on an FS12 gas seal) and got the same pressure signs. It seems that replacing the original wad system gets pressure spikes, as LongBow and others pointed out.

Aside from this, I reloaded some Lyman 525 slugs with original wads and my 3d printed sabots and got some pretty good results today...Including a 1.3" 5 shot group (my best group was on the last 5-shots of the day no less!) at 50 yards...Probably my best outing to date.

Anyway, I just wanted to thank everyone for the support. The current performance of the reloads (from cheap Walmart birdshot at about $0.24/each) is exceeding my expectations and I definitely couldn't have gotten there with out your help/suggestions/advice.

285544

285545

285546

[Cap'n Morgan]

Fine looking groups!

But I must repeat, and I can't stress this enough: NEVER substitute a compressible wad with a non-compressible one!

(Stop me if I'm getting long winded here, but...)

With fast burning powder maximum pressure is reached in about half a millisecond, and it peaks before the payload has begun to move.
A compressible wad is actually a form of "filler" - it takes up space and keep the powder up against the primer, but as the pressure rise
the wad compresses and increase the volume behind the payload. The pressure is directly related to volume, doubling the volume will
reduce the pressure by half, but it works both ways! When you add a non-compressible wad, you're reducing the volume = increasing pressure.
If you want to use a solid wad and a x12x seal it's perfectly alright, just reduce the amount of powder to make up for the reduced volume.

[mikehill85]

Fine looking groups!

But I must repeat, and I can't stress this enough: NEVER substitute a compressible wad with a non-compressible one!

(Stop me if I'm getting long winded here, but...)

With fast burning powder maximum pressure is reached in about half a millisecond, and it peaks before the payload has begun to move.
A compressible wad is actually a form of "filler" - it takes up space and keep the powder up against the primer, but as the pressure rise
the wad compresses and increase the volume behind the payload. The pressure is directly related to volume, doubling the volume will
reduce the pressure by half, but it works both ways! When you add a non-compressible wad, you're reducing the volume = increasing pressure.
If you want to use a solid wad and a x12x seal it's perfectly alright, just reduce the amount of powder to make up for the reduced volume.

I agree and thanks for the stern warning it is well taken. I've learned my lesson. The trouble with the cheap bird shot is the propellant is quite clearly very fast burning (there's only about 17.9 grains of the propellant and it managed to cause the pressure signs seen on this page and page 6 of this thread).

These types of loads have collapsing wads and you can't substitute them for anything else (not without playing Russian Roulette anyway). I thought the FS12 gas seal would give me a enough cushion because it is a cushioned gas seal but this clearly wasn't enough and I won't be trying that (or any type of wad substitution/weight payload increase (although I did that by accident), etc.,) ever again. I enjoy having all my fingers, eyes, etc., too much for that.

At the end of the day, I think the results of the 3d printed sabots speak for themselves and this experiment has been a success. I went from about 3"-4" groups with the stock shot cups to groups under 1.5" with sabots that cost pennies printed on a 3d printer that costs $200-$250 (and can be used for any number of other things). I can live with that and not touch the wad or any other part of the system.

I will definitely be experimenting more with the Svarog slug but not until I can get all the components for a known safe load.

[longbow]

Yes, I am on board with Cap'n Morgan and his explanation.

For the most part my slug loads have been loaded over Blue Dot. Two main reasons: 1) I started loading heavier than 1 oz. slugs (0.735" RB's actually) using Precision Rifle's loading specs for their PileDriver slug of 610 grs. and using Blue Dot; 2) I checked heavy birdshot loads and found recipes using Blue Dot and wads with little or no cushion leg.

Subsequently I looked at short hull loads with no cushion leg and compared to regular length hull loads with cushion legs. It appeared that they seemed to use less powder for same pressure and payload or ran higher pressure for same powder and payload as regular length hulls with cushion legs. This seemed to me to be more obvious with faster powders but my "research" was pretty crude and just cross referencing load data. Pressure testing would be the way to go.

So, I am cautious about removing cushion legs.

What would also be nice is to get hold of some old loading data before plastic wads and gas seals when only nitro cards, hard card wads and/or fiber wads were used. From my limited experience there is a lot of blow by/leakage so I am betting powder charges were larger for same pressure if a plastic gas seal is used. What percent increase in powder? Is it predictable? I have a bit of old timey reloading info but not a lot. I have looked but it seems not much is readily available. There are some sites where people post recipes for old shotguns and using card wad columns but I have as yet to turn up an old loading manual listing a variety of powders and payloads.

Also, on a slightly different topic, you mention types of plastics for 3D printing your wads. Not sure if you have seen them but Cap'n Morgan has a thread or two on his development of full bore and sabot style slugs here:

https://castboolits.gunloads.com/showthread.php?353062-New-slug-design&highlight=brenneke
https://castboolits.gunloads.com/showthread.php?246413-Brenneke-slugs-light-at-the-end-of-the-tunnel&highlight=brenneke

and BigMrTong here:

https://castboolits.gunloads.com/showthread.php?364546-Improvement-of-my-Good-1oz-Lee-Slug-Load&highlight=slug
https://castboolits.gunloads.com/showthread.php?358525-Lee-7-8oz-Custom-Slug-Wads&highlight=slug
https://castboolits.gunloads.com/showthread.php?355115-Sabot-Rounds-in-12g-Shotgun&highlight=slug

Cap'n Morgan isn't 3D printing and he has skills and access to equipment most of us don't but very good info and likely some info on the plastics he used so you could compare properties.

BigMrTong 3D printed his rocket fins and sabots so again there is likely some useful info there.

Both have been very helpful when I asked questions and I am still waiting on a friend to 3D print me some hybrid rocket fin designs where I have used info from both Cap'n Morgan and BigMrTong.

If you have seen those threads just ignore me, I am rambling again!

Longbow

[mikehill85]

Yes, I am on board with Cap'n Morgan and his explanation.

For the most part my slug loads have been loaded over Blue Dot. Two main reasons: 1) I started loading heavier than 1 oz. slugs (0.735" RB's actually) using Precision Rifle's loading specs for their PileDriver slug of 610 grs. and using Blue Dot; 2) I checked heavy birdshot loads and found recipes using Blue Dot and wads with little or no cushion leg.

Subsequently I looked at short hull loads with no cushion leg and compared to regular length hull loads with cushion legs. It appeared that they seemed to use less powder for same pressure and payload or ran higher pressure for same powder and payload as regular length hulls with cushion legs. This seemed to me to be more obvious with faster powders but my "research" was pretty crude and just cross referencing load data. Pressure testing would be the way to go.

So, I am cautious about removing cushion legs.

What would also be nice is to get hold of some old loading data before plastic wads and gas seals when only nitro cards, hard card wads and/or fiber wads were used. From my limited experience there is a lot of blow by/leakage so I am betting powder charges were larger for same pressure if a plastic gas seal is used. What percent increase in powder? Is it predictable? I have a bit of old timey reloading info but not a lot. I have looked but it seems not much is readily available. There are some sites where people post recipes for old shotguns and using card wad columns but I have as yet to turn up an old loading manual listing a variety of powders and payloads.

Also, on a slightly different topic, you mention types of plastics for 3D printing your wads. Not sure if you have seen them but Cap'n Morgan has a thread or two on his development of full bore and sabot style slugs here:

https://castboolits.gunloads.com/showthread.php?353062-New-slug-design&highlight=brenneke
https://castboolits.gunloads.com/showthread.php?246413-Brenneke-slugs-light-at-the-end-of-the-tunnel&highlight=brenneke

and BigMrTong here:

https://castboolits.gunloads.com/showthread.php?364546-Improvement-of-my-Good-1oz-Lee-Slug-Load&highlight=slug
https://castboolits.gunloads.com/showthread.php?358525-Lee-7-8oz-Custom-Slug-Wads&highlight=slug
https://castboolits.gunloads.com/showthread.php?355115-Sabot-Rounds-in-12g-Shotgun&highlight=slug

Cap'n Morgan isn't 3D printing and he has skills and access to equipment most of us don't but very good info and likely some info on the plastics he used so you could compare properties.

BigMrTong 3D printed his rocket fins and sabots so again there is likely some useful info there.

Both have been very helpful when I asked questions and I am still waiting on a friend to 3D print me some hybrid rocket fin designs where I have used info from both Cap'n Morgan and BigMrTong.

If you have seen those threads just ignore me, I am rambling again!

Longbow

No, not at all. Those are some great insights. I agree, it would be very interesting to find old load data on what people used before plastic sabots.

One thing I'd really like to figure out is what kind of powder I am dealing with. I haven't found good data on what it is that Federal uses in their Field and Target Loads. Maybe it varies or they keep it under wraps but if I knew what powder it was I could perhaps find a safe known load for non-collapsing tail wads.

Yeah, I was trying to get a line on some Blue Dot but everything is sold out atm. I have e-mail alerts out for when it does come available again though. I definitely think a slower burning powder is in order for slugs like the Lyman 525 (at least to get it up to velocities that would allow you to stretch out past 50 yards).

Those threads are great! Thanks for sharing! Really cool stuff from Cap'n Morgan and BigMrTong. By complete coincidence I actually ordered the Lee Drive Key 7/8 oz slug mold today, since I had been watching it and the price dropped. I like the fact the drive key slug has the section in the middle which you can attach something to so that I would definitely transfer the spin from my rifled choke tube. Also the fact the 7/8 oz slug is a lighter payload than the loads I'm repurposing should help keep pressures down. Once I get it, I'll play around with some designs to get it up to bore diameter (while reusing the collapsing wad). If I do that, the pressures should be lower than with the lead birdshot load because that payload is heavier.

I have had this mold in the past but it galled. I think I was probably not lubricating it properly and running it too hot. I recently built my own PID controller which monitors and controls the pot temperature to within 5 F or so, so I'm hoping this time the mold will last longer.

Looking at Cap'n Morgan's thread reminded me of another interesting thing about 3d printing. With fairly sparse equipment you can create negatives for aluminum castings. You basically take a plastic 3d printed negative, put that negative in a mix of plaster of Paris and play sand (and let it harden), burn out the plastic negative, and fill the now empty cavity with molten aluminum. I have done this successfully in the past with things like statues. I'm not set up to do it right now but down the road I might look at doing this to make a slug mold. I'd probably need to clean up the casting afterwards but I think it's a plausible method to make your own custom aluminum slug mold.

Below is an example of a statue I cast in Aluminum (I built an Aluminum smelting furnace out of an old galvanized steel bucket, refractory cement, and a propane torch for burning weeds). It's not perfect but you get the idea. You can cast just about any shape you can imagine and it definitely holds detail...You can even see the layer lines from the 3d print.

285557

[longbow]

I only have a few Lee moulds but they work well. Both my slug moulds (1 oz. and 7/8 oz.) needed a bit of deburring when I got them but both literally drop slugs now. I use sprue plate lube and powdered graphite to lubricate the mould tops, core pins and the Vee guides in my old style 1 oz. slug mould. I have found that the old style Vee guides tend to gall fairly easily and Lee moulds are soft aluminum. So far the sprue plate lube and graphite have worked well for me. A little dab will do ya!

I modified the core pins to add a post and screw hole for attached wads. It is a very easy modification to do if you have a lathe and does not seem to affect slug balance so they can be used as intended or with an attached wad. The weight is a little higher by about 1/8 oz. powder charge is adjusted accordingly. I had bought a couple of spare core pins for $1.50 ea. and see they now cost $14.00 ea.! I shouldn't need any more but had planned to buy a couple just in case. At $14.00 I'll just buy spare moulds. I get a core pin and mould for about twice the cost of core pin alone.

I plan to try a few different approaches to attached wads once my friend gets to 3D printing again. In the meantime I have to get back to making hot melt glue attached wads for those slugs. I made a form at about the same diameter of the nose at 0.685" then line it with a wrap and a bit of parchment paper then use my glue gun to squirt glue into it until a bit over full. The form is standing vertical so bubbles rise to the top and shrinkage is all in the top. After the glue hardens I cut the end off then use a jig to cut 3/8" thick disks off. These become the attached wads. So far it seems to be the easiest and most consistent method for me. Now to get out and shoot some! Was planning that for last week but didn't make it. Hopefully next week.

Longbow

[Yrmff!!]

very sorry for the slow reply. For that model i used elgoo grey resin and i used an elgoo mars 3d printer. I haven't actually tested this iteration yet unfortunately, due to the pandemic and the general lack of ammunition. Which 3d printer i would get now depends on the application. If you want to 3d print things that are smaller and could benefit from an absurd level of detail (literally down to about 1/10 the thickness of a human hair), i would get a resin printer like the elegoo mars 2 or whichever similar printer happens to be on sale. The majority of these resin printers pretty much use the same design and same screen. Just make sure you get one that has a monochrome screen. They can print about 3 times faster than the color screen version.

If wanted a printer to print larger objects in a variety of materials, i would consider getting an fdm printer. There are many different versions you can choose from but just make sure to get one with an all-metal hot end that will let you print higher temperature materials. I have a lulzbot mini but they are expensive and i would recommend a budget option to start out with to see if you like it. If i were getting one now i'd probably look at that prusa mini or the ender 3. The ender 3 has a bigger print volume than the mini but the mini has self-leveling and a hot end with a higher maximum temperature (which means you can print higher temperature materials). I personally have lulzbot mini with a similar print volume to the mini and basically never find myself needing anything bigger but which you should chose if you go with fdm is dependent on your application. The prusa mini should do you for 95% of what you need. If you need to print something larger you can probably break it up into multiple parts and i think the ability to print more materials is worth the small difference in print volume. I would go with prusa mini+ if you're going with an fdm printer.

That being said, if you are just getting into 3d printing, the resin printers are hard to beat. The level of detail you can achieve with your prints is insane and far exceeds what you'll ever get on an fdm printer. They are also probably easier to use and give you results that you'll be happy with. A good resin print literally looks like it is injection molded as post #76 will attest to. Also resin printers are cheap, the resins are also relatively cheap now (and getting cheaper), and the resins are being offered with various properties now (and expanding in the range of material properties). I would personally recommend looking into something like an elegoo mars 2 with the monochrome screen. They are about $300 usd on amazon now but you might be able to find something with the same specs (and pretty much the exact same printer) from a different brand for about $250. Just be aware that the $250-$300 resin printers only give you a print area of about the size of a large cellphone screen and the range of material properties of resin doesn't currently compare to fdm but i do think resin is the future of 3d printing for the most part due to the flawless print quality and dimensional accuracy you can achieve. You can get larger resin printers but they are about $900-$2,000.

If you or anyone else are interested in the 3d model files for this project i'd be happy to share them, including the fusion360 source files which you could modify to your heart's content. I don't have a problem sharing with experienced reloaders but wouldn't post this design for the general public because they might get themselves hurt due to lack of reloading experience which as we know can be dangerous if not done properly.

Also, feel free to reply to my post here with any questions. I should respond fast now. I didn't know that i could link this thread to my e-mail and receive notifications when someone posts on this thread until now.

pm :)